Fog forecast — Friday 16 October

dashboard · tonight · 7-day outlook · region: Grayslake / Lake County

run 2026-10-16T00:24-05:00 · Platt-calibrated on 329 station-mornings (2026-08-21..2026-10-15 at GYY, IKK, JOT, LOT, PNT, RZL)

No fog morning.

fog probability at home 1 % · high confidence

Typeshallow ground fog · 0–3 m, if any (estimate) Sky at sunriseno fog expected; mid+high cloud at sunrise ≈ 0 %, plus a low deck ≈ 59 % with visibility 16 km (stratus, not fog) — beams possible through gaps If you go06:37 (civil dawn) · sunrise 07:06 at 101.5° ESE Beamssun 2°–12° up: 07:20–08:19 At sunrise9.3 °C / 49 °F, wind 9 kt (HRRR) Burn-offnot applicable at this probability

Why: the primary model never brings T−Td under 1 °C (minimum 2.1 °C); anything that forms will be thin patches over water and the wettest low ground.
HRRR profile at KUGN 07:00 (run 2026-10-15 19:00): no level saturated (T−Td ≤ 1 °C), temperature change 10 m → 80 m: -0.4 °C — profile shows no saturated layer at the airport; any fog will be local to low ground and water
River steam fog unlikely: river water +8.7 °C warmer than the forecast dawn air (steam fog over open water needs roughly ≥5 °C and light wind; forecast wind 12 kt)
4 models within 0.07 of each other on the blend score

Sites, best first

site	fog	grade	type	light	sunrise	drive	drone
Grayslake (village center)	1 %	F	shallow ground fog	filtered sun	07:06 · 101.5° ESE	— min	unknown
Brae Loch Golf Club	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	8 min	permit
Grayslake Golf Course	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	7 min	unknown
Renwood Golf Course	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	7 min	unknown
Village Green Country Club	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	8 min	unknown
Bittersweet Golf Club	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	11 min	unknown
HeatherRidge Golf Course	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	12 min	unknown
Pine Meadow Golf Club	1 %	F	shallow ground fog	filtered sun	07:06 · 101.5° ESE	13 min	unknown
Ivanhoe Club	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	13 min	unknown
Hickory Knoll Golf Course	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	14 min	unknown
Merit Club	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	14 min	unknown
Steeple Chase Golf Club	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	15 min	unknown
Stonewall Orchard Golf Club	1 %	F	shallow ground fog	filtered sun	07:06 · 101.5° ESE	18 min	unknown
Rollins Savanna Forest Preserve	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	7 min	permit
Almond Marsh Forest Preserve	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	9 min	permit
Lakewood Forest Preserve	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	14 min	permit
Grant Woods Forest Preserve	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	15 min	permit
Volo Bog State Natural Area	1 %	F	shallow ground fog	filtered sun	07:07 · 101.5° ESE	19 min	permit
Chain O'Lakes State Park	1 %	F	shallow ground fog	overcast above the fog	07:07 · 101.5° ESE	30 min	permit
Third Lake	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	11 min	unknown
Gages Lake	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	9 min	unknown
Fourth Lake	1 %	F	shallow ground fog	overcast above the fog	07:06 · 101.5° ESE	14 min	unknown

Grayslake (village center) — 1 %, shallow ground fog

Where42.3434, -88.0412 · map Featureslakes, wetland, golf Accessnot verified Droneunknown — no rule found NotesVillage center from OpenStreetMap Nominatim (42.3433518, -88.0412192), fetched 16 Oct 2026 Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Riverriver water +8.7 °C warmer than the forecast dawn air (steam fog over open water needs roughly ≥5 °C and light wind; forecast wind 12 kt) Rain 48 h17.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.38 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.07 — mean 10 m wind in the 3 h before sunrise = 11.6 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.88 — overnight mid+high levels cloud = 29 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 6.1 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.3 °C vs afternoon dewpoint 13.8 °C → -4.5 °C; rain last 48 h = 17.5 mm; BUT dewpoint falls 6.7 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.3 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 84 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.053, ncep_nbm_conus 0.108, ecmwf_ifs025 0.073, icon_seamless 0.036 · spread 0.072

local	T	Td	T−Td	wind	low	mid	vis km
21:00	16.1	15.6	0.5	7.3	100	15	12.2
22:00	15.8	14.3	1.5	11.6	100	24	13.8
23:00	14.5	12.8	1.7	11.5	100	82	14.1
00:00	13.5	11.6	1.9	12.2	90	100	14.7
01:00	13.0	10.7	2.3	13.3	100	100	15.8
02:00	12.4	10.3	2.1	11.4	100	0	15.3
03:00	11.6	9.2	2.4	14.3	100	0	16.1
04:00	10.9	8.5	2.4	13.8	59	0	16.0
05:00	10.4	8.3	2.1	11.4	62	0	15.3
06:00	10.0	7.6	2.4	11.9	100	0	16.0
07:00	9.3	7.1	2.2	9.3	18	0	15.7
08:00	9.7	7.6	2.1	11.4	100	0	15.3
09:00	9.5	7.2	2.3	10.6	100	0	15.7
10:00	10.3	7.3	3.0	12.0	100	0	17.9
11:00	9.7	6.9	2.8	12.5	100	0	16.8

Brae Loch Golf Club — 1 %, shallow ground fog

Where42.3491, -88.0092 · map Featurespond, mature trees, gentle rolling terrain, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Dronepermit — LCFP Regulations Governing the General Use of District Property (approved Jan 14 2020, amended Jan 17 2024), Sec. III.A: "No person shall use District Property for any of the following uses, unless the person has first obtained, and has physical possession of, a Permit allowing such use"; item (v): "use of any fuel-powered, air-propulsion, electric powered, radio-controlled, or cellular-controlled unmanned aerial Vehicle (commonly referred to as a \"drone\"), model or toy car, aircraft, boat or rocket, or any similar toy or model"; item (xx): "taking any still or motion pictures ... for commercial purposes or for use in commercial advertising". LCFP's fee ordinance lists a 'Commercial Photography, Film or Video Permit'. Read from a Wayback copy (2024-02-25) because lcfpd.org returns a Cloudflare 403 to scripted fetches. No drone-specific permit procedure found; the model-aircraft page (archived 2026-02-15) offers only the Van Patten Woods field. A 2014 staff memo, seen only as a search-result excerpt, said drones may not launch or land elsewhere in the preserves. source AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 3.7 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 3.3 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. Closest golf course to KUGN's boundary after Bittersweet/Heather Ridge/Merit. NotesOWNERSHIP CORRECTION: the ticket listed Brae Loch under Lake County Forest Preserves and the course site confirms it (header 'Lake County Forest Preserves'; FAQ says 'all three Lake County Forest Preserves courses'). That makes it District Property, so the LCFP drone-permit rule applies on top of any owner consent. Course hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h17.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.38 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.06 — mean 10 m wind in the 3 h before sunrise = 11.7 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.89 — overnight mid+high levels cloud = 28 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.8 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.5 °C vs afternoon dewpoint 13.8 °C → -4.3 °C; rain last 48 h = 17.5 mm; BUT dewpoint falls 6.6 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.3 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 86 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.053, ncep_nbm_conus 0.108, ecmwf_ifs025 0.073, icon_seamless 0.036 · spread 0.072

local	T	Td	T−Td	wind	low	mid	vis km
21:00	16.3	15.8	0.5	7.9	100	13	12.2
22:00	15.9	14.4	1.5	11.9	100	33	13.8
23:00	14.6	12.9	1.7	11.7	100	63	14.0
00:00	13.6	11.6	2.0	12.6	91	100	14.8
01:00	13.0	10.7	2.3	13.6	100	100	15.6
02:00	12.3	10.0	2.3	11.9	100	0	15.6
03:00	11.7	9.6	2.1	14.4	100	0	15.6
04:00	11.0	8.5	2.5	13.8	54	0	16.2
05:00	10.6	8.5	2.1	11.4	82	0	15.3
06:00	10.1	7.9	2.2	12.2	100	0	15.9
07:00	9.5	7.2	2.3	9.5	22	0	15.8
08:00	9.7	7.6	2.1	11.5	100	0	15.3
09:00	9.6	7.3	2.3	10.7	100	0	15.6
10:00	10.4	7.5	2.9	11.8	100	0	17.8
11:00	9.8	7.2	2.6	12.4	100	0	16.7

Grayslake Golf Course — 1 %, shallow ground fog

Where42.3756, -88.0346 · map Featureswetland, pond, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Droneunknown — No drone rule found on the pages reached. Policies page (grayslakegolfcourse.com/policies) covers carts, minors and errant balls only. 620 ILCS 5/42.1(b-5) (per ticket C research) lets a local government adopt reasonable rules over its own recreation land; none located. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 3.9 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 3.5 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesCourse is not mapped as a golf_course polygon in OSM, so the coordinate is the road geocode. The only 'protected wetlands' claim is from a search summary of GolfAdvisor, not used. Walking-only course, 1,200 yards, address 2150 Drury Lane 60030. Same street name as Rollins Savanna's Drury Lane lot (Visit Lake County page); adjacency not verified. Course hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h17.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.38 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.06 — mean 10 m wind in the 3 h before sunrise = 11.8 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.87 — overnight mid+high levels cloud = 30 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 6.0 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.3 °C vs afternoon dewpoint 13.7 °C → -4.4 °C; rain last 48 h = 17.5 mm; BUT dewpoint falls 6.8 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.3 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 87 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.053, ncep_nbm_conus 0.108, ecmwf_ifs025 0.07, icon_seamless 0.036 · spread 0.072

local	T	Td	T−Td	wind	low	mid	vis km
21:00	15.8	15.3	0.5	7.1	100	14	12.2
22:00	15.8	14.3	1.5	11.7	100	28	13.8
23:00	14.5	12.9	1.6	11.7	100	84	14.1
00:00	13.5	11.6	1.9	12.6	100	100	14.9
01:00	13.0	10.7	2.3	13.6	100	100	15.6
02:00	12.2	9.9	2.3	11.9	72	0	15.8
03:00	11.7	9.6	2.1	14.0	100	0	15.1
04:00	11.0	8.5	2.5	13.8	68	0	16.3
05:00	10.6	8.5	2.1	11.6	93	0	15.3
06:00	10.1	7.7	2.4	12.1	100	0	16.1
07:00	9.3	6.9	2.4	9.5	23	0	15.9
08:00	9.8	7.6	2.2	11.4	100	0	15.5
09:00	9.5	7.5	2.0	10.7	100	0	15.4
10:00	10.4	7.4	3.0	12.2	100	0	18.0
11:00	9.7	7.1	2.6	12.5	100	0	16.7

Renwood Golf Course — 1 %, shallow ground fog

Where42.3708, -88.0645 · map Featurespond, stream, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Droneunknown — No drone rule found on the pages reached. 620 ILCS 5/42.1(b-5) (per ticket C research) lets a local government adopt reasonable rules over its own recreation land; none located. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 5.3 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 4.9 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesRound Lake Beach mailing address, touches the west edge of Grayslake. Course hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h23.1 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.35 — min T−Td in the 3 h before sunrise = 2.2 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.07 — mean 10 m wind in the 3 h before sunrise = 11.5 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.84 — overnight mid+high levels cloud = 32 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 6.0 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.4 °C vs afternoon dewpoint 13.8 °C → -4.4 °C; rain last 48 h = 23.1 mm; BUT dewpoint falls 6.8 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.5 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 86 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.051, ncep_nbm_conus 0.109, ecmwf_ifs025 0.073, icon_seamless 0.035 · spread 0.074

local	T	Td	T−Td	wind	low	mid	vis km
21:00	15.8	15.2	0.6	6.6	100	16	12.2
22:00	15.8	14.3	1.5	11.7	100	35	13.8
23:00	14.5	12.9	1.6	11.3	100	100	14.3
00:00	13.5	11.6	1.9	12.2	100	100	14.9
01:00	13.0	10.7	2.3	13.4	100	100	15.8
02:00	12.2	9.9	2.3	11.7	100	0	15.8
03:00	11.7	9.4	2.3	14.1	100	0	15.8
04:00	11.0	8.6	2.4	13.7	46	0	16.2
05:00	10.7	8.5	2.2	11.4	72	0	15.5
06:00	10.2	7.6	2.6	11.9	100	0	16.3
07:00	9.4	7.0	2.4	9.1	23	0	15.8
08:00	9.8	7.5	2.3	11.3	100	0	15.4
09:00	9.6	7.3	2.3	10.6	100	0	15.5
10:00	10.4	7.1	3.3	12.2	100	0	18.2
11:00	9.8	7.1	2.7	12.3	100	0	16.9

Village Green Country Club — 1 %, shallow ground fog

Where42.2984, -88.0186 · map Featurespond, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Droneunknown — No drone rule found on the pages reached. Official site not reached (villagegreencc.com failed to connect). AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 6.0 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 5.5 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesPublic status comes only from search-result summaries of GolfPass/OpenGolfAPI, not an official page. Course hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h12.3 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.38 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.00 — mean 10 m wind in the 3 h before sunrise = 13.1 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.93 — overnight mid+high levels cloud = 25 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.8 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.39 — crossover: forecast night minimum 9.5 °C vs afternoon dewpoint 13.9 °C → -4.4 °C; rain last 48 h = 12.3 mm; BUT dewpoint falls 6.6 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.4 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 13 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 88 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.052, ncep_nbm_conus 0.106, ecmwf_ifs025 0.072, icon_seamless 0.036 · spread 0.07

local	T	Td	T−Td	wind	low	mid	vis km
21:00	17.0	16.5	0.5	8.7	100	12	12.2
22:00	15.9	14.6	1.3	12.6	100	29	13.6
23:00	14.5	12.9	1.6	12.9	100	37	14.0
00:00	13.5	11.8	1.7	13.7	100	100	14.5
01:00	12.9	10.8	2.1	15.1	91	100	15.4
02:00	12.4	10.6	1.8	12.8	100	0	14.6
03:00	11.6	9.3	2.3	16.4	100	0	15.8
04:00	10.9	8.7	2.2	15.4	77	0	15.8
05:00	10.6	8.5	2.1	13.1	74	0	15.4
06:00	10.0	7.8	2.2	13.4	100	0	15.8
07:00	9.5	7.3	2.2	10.6	30	0	15.9
08:00	9.6	7.7	1.9	12.3	100	0	15.0
09:00	9.4	7.2	2.2	12.3	100	0	15.7
10:00	10.2	7.6	2.6	12.0	100	0	17.2
11:00	9.6	7.1	2.5	12.9	100	0	16.7

Bittersweet Golf Club — 1 %, shallow ground fog

Where42.3723, -87.9800 · map Featurespond, wetland, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Droneunknown — No drone rule found on the pages reached. 620 ILCS 5/42.1(b-5) (per ticket C research) lets a local government adopt reasonable rules over its own recreation land; none located. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 1.8 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 1.5 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. CLOSEST to KUGN of the golf courses: 1.8 nm from the Class D edge at the geocoded point; the course is large, so check the actual launch point. NotesMost water of any course in OSM (17 polygons). Course hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h17.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.37 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.05 — mean 10 m wind in the 3 h before sunrise = 12.0 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.86 — overnight mid+high levels cloud = 31 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.8 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.5 °C vs afternoon dewpoint 13.8 °C → -4.2 °C; rain last 48 h = 17.5 mm; BUT dewpoint falls 6.7 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.4 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 88 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.052, ncep_nbm_conus 0.108, ecmwf_ifs025 0.073, icon_seamless 0.036 · spread 0.072

local	T	Td	T−Td	wind	low	mid	vis km
21:00	16.0	15.5	0.5	7.7	100	10	12.2
22:00	15.9	14.3	1.6	11.9	100	39	14.0
23:00	14.7	13.0	1.7	11.9	100	89	14.0
00:00	13.7	11.8	1.9	12.8	100	100	15.0
01:00	13.1	11.0	2.1	13.5	100	100	15.4
02:00	12.2	9.9	2.3	12.0	61	0	15.8
03:00	11.8	10.0	1.8	13.8	100	0	14.7
04:00	11.2	8.6	2.6	13.9	83	0	16.5
05:00	10.8	8.7	2.1	11.9	100	0	15.4
06:00	10.3	7.9	2.4	12.3	100	0	16.0
07:00	9.5	7.1	2.4	10.0	23	0	16.1
08:00	9.9	7.6	2.3	10.9	100	0	15.6
09:00	9.7	7.6	2.1	11.2	100	0	15.4
10:00	10.4	7.5	2.9	11.7	100	0	17.7
11:00	9.8	7.2	2.6	12.8	100	0	16.7

HeatherRidge Golf Course — 1 %, shallow ground fog

Where42.3484, -87.9524 · map Featurespond, stream, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Droneunknown — No drone rule found on the pages reached. OSM-listed site heatherridgegolf.com served an unrelated spam page on 2026-10-16. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 1.8 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 1.4 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. Edge of KUGN Class D at about 1.8 nm; re-check at launch point. NotesOperating status and management from search-result summaries (GolfNow, Visit Lake County), no official page reached. Course hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h17.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.35 — min T−Td in the 3 h before sunrise = 2.2 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.07 — mean 10 m wind in the 3 h before sunrise = 11.7 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.86 — overnight mid+high levels cloud = 31 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.6 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.7 °C vs afternoon dewpoint 13.6 °C → -3.9 °C; rain last 48 h = 17.5 mm; BUT dewpoint falls 6.5 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.6 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 87 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.051, ncep_nbm_conus 0.109, ecmwf_ifs025 0.073, icon_seamless 0.036 · spread 0.073

local	T	Td	T−Td	wind	low	mid	vis km
21:00	16.6	16.0	0.6	7.8	100	4	12.2
22:00	16.1	14.5	1.6	11.2	100	72	14.2
23:00	14.8	13.1	1.7	11.9	100	62	14.2
00:00	13.9	11.8	2.1	12.2	91	100	15.2
01:00	13.3	11.0	2.3	13.3	100	100	15.5
02:00	12.4	10.0	2.4	12.0	58	0	16.0
03:00	11.9	10.1	1.8	13.8	100	0	14.7
04:00	11.4	8.8	2.6	13.7	82	0	16.7
05:00	10.8	8.6	2.2	11.5	100	0	15.6
06:00	10.4	8.0	2.4	11.9	100	0	16.1
07:00	9.7	7.1	2.6	9.5	31	0	16.4
08:00	9.9	7.7	2.2	10.1	100	0	15.8
09:00	9.9	7.6	2.3	11.1	100	0	15.8
10:00	10.5	7.5	3.0	10.6	100	0	17.6
11:00	10.1	7.3	2.8	12.2	100	0	17.2

Pine Meadow Golf Club — 1 %, shallow ground fog

Where42.2901, -87.9886 · map Featurespond, wetland, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Droneunknown — No drone rule found on the pages reached. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 5.6 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 5.0 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesMundelein/Libertyville line. Course hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h12.3 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.32 — min T−Td in the 3 h before sunrise = 2.3 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.03 — mean 10 m wind in the 3 h before sunrise = 12.4 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.92 — overnight mid+high levels cloud = 26 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.8 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.39 — crossover: forecast night minimum 9.6 °C vs afternoon dewpoint 13.8 °C → -4.2 °C; rain last 48 h = 12.3 mm; BUT dewpoint falls 6.6 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.6 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 86 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.05, ncep_nbm_conus 0.107, ecmwf_ifs025 0.072, icon_seamless 0.037 · spread 0.07

local	T	Td	T−Td	wind	low	mid	vis km
21:00	17.3	16.8	0.5	7.5	100	9	12.2
22:00	16.1	14.6	1.5	11.5	100	41	13.7
23:00	14.8	13.0	1.8	12.3	100	36	14.3
00:00	13.8	11.9	1.9	12.5	100	100	14.8
01:00	13.1	10.8	2.3	14.0	96	100	15.7
02:00	12.6	10.5	2.1	11.9	100	0	15.3
03:00	11.9	9.6	2.3	15.1	100	0	15.7
04:00	11.2	8.8	2.4	14.6	70	0	16.3
05:00	10.5	8.2	2.3	12.1	60	0	15.6
06:00	10.2	7.8	2.4	12.8	100	0	16.1
07:00	9.6	7.2	2.4	10.0	22	0	16.2
08:00	9.9	7.8	2.1	11.3	88	0	15.5
09:00	9.7	7.4	2.3	11.1	100	0	15.9
10:00	10.3	7.5	2.8	10.7	100	0	17.3
11:00	9.9	7.1	2.8	11.9	100	0	17.0

Ivanhoe Club — 1 %, shallow ground fog

Where42.2812, -88.0643 · map Featurescreek, pond, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Droneunknown — No drone rule found on the pages reached. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 8.0 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 7.6 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesPrivate members' club, Mundelein. Course hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h12.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.38 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.00 — mean 10 m wind in the 3 h before sunrise = 13.2 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.94 — overnight mid+high levels cloud = 24 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.9 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.39 — crossover: forecast night minimum 9.6 °C vs afternoon dewpoint 13.9 °C → -4.3 °C; rain last 48 h = 12.5 mm; BUT dewpoint falls 6.6 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.3 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 13 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 90 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.052, ncep_nbm_conus 0.106, ecmwf_ifs025 0.072, icon_seamless 0.038 · spread 0.068

local	T	Td	T−Td	wind	low	mid	vis km
21:00	16.9	16.4	0.5	9.0	100	11	12.2
22:00	15.9	14.4	1.5	12.9	100	18	13.7
23:00	14.5	12.9	1.6	12.9	100	39	14.0
00:00	13.6	11.8	1.8	13.7	100	100	14.5
01:00	12.9	10.8	2.1	14.8	100	99	15.4
02:00	12.4	10.8	1.6	12.9	100	0	14.0
03:00	11.6	9.4	2.2	16.6	100	0	15.8
04:00	11.0	8.9	2.1	15.4	82	0	15.5
05:00	10.6	8.5	2.1	13.2	73	0	15.3
06:00	10.0	7.8	2.2	13.4	100	0	15.7
07:00	9.6	7.3	2.3	10.6	35	0	15.7
08:00	9.6	7.7	1.9	12.3	100	0	15.0
09:00	9.5	7.2	2.3	12.7	100	0	15.8
10:00	10.3	7.5	2.8	12.8	100	0	17.4
11:00	9.7	7.1	2.6	13.5	100	0	16.9

Hickory Knoll Golf Course — 1 %, shallow ground fog

Where42.3990, -88.1155 · map Featureshilly terrain, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Droneunknown — No drone rule found on the pages reached. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Not under the Class B shelf; Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 7.1 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 7.0 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. Beyond the Class B shelf at this point (no Class B polygon). NotesWeakest fog candidate of the courses: no water, above its ring. Course hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h23.1 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.40 — min T−Td in the 3 h before sunrise = 2.0 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.05 — mean 10 m wind in the 3 h before sunrise = 11.9 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.85 — overnight mid+high levels cloud = 32 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 6.1 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.1 °C vs afternoon dewpoint 13.7 °C → -4.6 °C; rain last 48 h = 23.1 mm; BUT dewpoint falls 6.6 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.2 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: precipitation around dawn (0.4 mm): drizzle/rain, not radiation fog
GATE ×0.6: low cloud deck 87 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.032, ncep_nbm_conus 0.11, ecmwf_ifs025 0.071, icon_seamless 0.036 · spread 0.078

local	T	Td	T−Td	wind	low	mid	vis km
21:00	15.6	15.0	0.6	5.8	100	8	12.2
22:00	15.5	14.0	1.5	11.6	100	43	13.7
23:00	14.2	12.6	1.6	11.5	100	100	14.2
00:00	13.2	11.3	1.9	12.2	100	100	14.7
01:00	12.8	10.3	2.5	14.0	89	94	16.1
02:00	12.1	9.8	2.3	11.5	90	0	15.5
03:00	11.4	9.1	2.3	14.6	100	2	15.9
04:00	10.8	8.6	2.2	14.1	57	0	15.6
05:00	10.4	8.3	2.1	12.2	67	0	15.2
06:00	10.0	7.5	2.5	12.5	100	0	16.2
07:00	9.1	7.1	2.0	8.9	51	0	15.2
08:00	9.6	7.5	2.1	11.0	100	0	15.3
09:00	9.4	7.1	2.3	11.0	100	0	15.4
10:00	10.2	7.0	3.2	13.5	100	0	18.1
11:00	9.7	6.9	2.8	12.6	100	0	17.0

Merit Club — 1 %, shallow ground fog

Where42.3350, -87.9596 · map Featurespond, wetland, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Droneunknown — No drone rule found on the pages reached. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 2.6 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 2.1 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesCourse hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h17.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.35 — min T−Td in the 3 h before sunrise = 2.2 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.07 — mean 10 m wind in the 3 h before sunrise = 11.7 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.86 — overnight mid+high levels cloud = 31 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.6 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.7 °C vs afternoon dewpoint 13.6 °C → -3.9 °C; rain last 48 h = 17.5 mm; BUT dewpoint falls 6.5 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.6 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 87 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.051, ncep_nbm_conus 0.108, ecmwf_ifs025 0.073, icon_seamless 0.036 · spread 0.072

local	T	Td	T−Td	wind	low	mid	vis km
21:00	16.6	16.0	0.6	7.8	100	4	12.2
22:00	16.1	14.5	1.6	11.2	100	72	14.2
23:00	14.8	13.1	1.7	11.9	100	62	14.2
00:00	13.9	11.8	2.1	12.2	91	100	15.2
01:00	13.3	11.0	2.3	13.3	100	100	15.5
02:00	12.4	10.0	2.4	12.0	58	0	16.0
03:00	11.9	10.1	1.8	13.8	100	0	14.7
04:00	11.4	8.8	2.6	13.7	82	0	16.7
05:00	10.8	8.6	2.2	11.5	100	0	15.6
06:00	10.4	8.0	2.4	11.9	100	0	16.1
07:00	9.7	7.1	2.6	9.5	31	0	16.4
08:00	9.9	7.7	2.2	10.1	100	0	15.8
09:00	9.9	7.6	2.3	11.1	100	0	15.8
10:00	10.5	7.5	3.0	10.6	100	0	17.6
11:00	10.1	7.3	2.8	12.2	100	0	17.2

Steeple Chase Golf Club — 1 %, shallow ground fog

Where42.2626, -88.0537 · map Featurespond, wetland, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Droneunknown — No drone rule found on the pages reached. 620 ILCS 5/42.1(b-5) (per ticket C research) lets a local government adopt reasonable rules over its own recreation land; none located. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 8.7 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 8.1 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesEdge of the 15-minute limit (OSRM 14.6 min). Course hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h12.3 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.38 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.00 — mean 10 m wind in the 3 h before sunrise = 13.2 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.96 — overnight mid+high levels cloud = 23 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.9 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.39 — crossover: forecast night minimum 9.6 °C vs afternoon dewpoint 13.8 °C → -4.2 °C; rain last 48 h = 12.3 mm; BUT dewpoint falls 6.5 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.4 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 13 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 92 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.053, ncep_nbm_conus 0.104, ecmwf_ifs025 0.072, icon_seamless 0.037 · spread 0.067

local	T	Td	T−Td	wind	low	mid	vis km
21:00	17.2	16.7	0.5	8.6	100	11	12.2
22:00	15.8	14.5	1.3	12.9	100	17	13.5
23:00	14.5	12.8	1.7	13.1	100	33	14.0
00:00	13.6	11.8	1.8	13.7	100	100	14.7
01:00	12.9	10.7	2.2	14.8	96	91	15.5
02:00	12.3	10.7	1.6	13.3	100	0	13.9
03:00	11.5	9.2	2.3	16.4	100	0	15.8
04:00	10.9	8.8	2.1	15.2	100	0	15.5
05:00	10.6	8.5	2.1	13.2	74	0	15.4
06:00	10.0	7.8	2.2	13.4	100	0	15.8
07:00	9.6	7.3	2.3	10.8	47	0	15.9
08:00	9.5	7.6	1.9	12.1	100	0	15.2
09:00	9.4	7.1	2.3	12.4	100	0	15.7
10:00	10.0	7.4	2.6	12.4	100	0	17.1
11:00	9.6	7.0	2.6	13.2	100	0	16.9

Stonewall Orchard Golf Club — 1 %, shallow ground fog

Where42.3121, -88.1274 · map Featureswetland, pond, rolling hills, golf Lookfairway fog over ponds and tree lines at sunrise; drone from the course if this is the client's (owner's permission settled); Class G at the surface, no LAANC AccessNone Droneunknown — No drone rule found on the pages reached. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 9.3 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 8.9 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesOVER the 15-minute limit (OSRM 18.3 min) but kept because it has a Grayslake 60030 address. Course hours not found on the pages reached. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h12.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.37 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.00 — mean 10 m wind in the 3 h before sunrise = 12.9 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.84 — overnight mid+high levels cloud = 32 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 6.1 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.39 — crossover: forecast night minimum 9.4 °C vs afternoon dewpoint 13.8 °C → -4.4 °C; rain last 48 h = 12.5 mm; BUT dewpoint falls 6.6 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.4 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 13 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 88 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.05, ncep_nbm_conus 0.106, ecmwf_ifs025 0.075, icon_seamless 0.037 · spread 0.069

local	T	Td	T−Td	wind	low	mid	vis km
21:00	16.3	15.6	0.7	7.4	100	12	12.2
22:00	15.6	14.1	1.5	12.9	100	43	14.0
23:00	14.4	12.7	1.7	12.6	100	100	14.3
00:00	13.4	11.4	2.0	13.2	100	100	14.8
01:00	12.8	10.7	2.1	13.7	100	94	15.5
02:00	12.2	10.7	1.5	12.8	100	0	13.5
03:00	11.4	9.0	2.4	16.4	100	1	16.1
04:00	10.8	8.7	2.1	15.0	100	0	15.4
05:00	10.5	8.2	2.3	13.2	49	0	15.6
06:00	10.0	7.6	2.4	13.2	100	0	16.0
07:00	9.4	7.2	2.2	10.3	18	0	15.8
08:00	9.6	7.3	2.3	12.6	100	0	15.6
09:00	9.4	7.0	2.4	12.4	100	0	15.9
10:00	10.2	7.0	3.2	13.5	100	0	18.0
11:00	9.7	7.0	2.7	13.4	100	0	17.3

Rollins Savanna Forest Preserve — 1 %, shallow ground fog

Where42.3732, -88.0289 · map Featureswetland, savanna, prairie, oak grove, marsh, stream Lookmarsh and savanna fog from the ground at 6:30 opening; drone needs a Lake County Forest Preserves permit Access"Hours: 6:30 am-sunset, daily." (lcfpd.org page, Wayback copy 2025-09-14; live page Cloudflare-blocked). Banner: "Most preserves open 6:30 am-sunset." Dronepermit — LCFP Regulations Governing the General Use of District Property (approved Jan 14 2020, amended Jan 17 2024), Sec. III.A: "No person shall use District Property for any of the following uses, unless the person has first obtained, and has physical possession of, a Permit allowing such use"; item (v): "use of any fuel-powered, air-propulsion, electric powered, radio-controlled, or cellular-controlled unmanned aerial Vehicle (commonly referred to as a \"drone\"), model or toy car, aircraft, boat or rocket, or any similar toy or model"; item (xx): "taking any still or motion pictures ... for commercial purposes or for use in commercial advertising". LCFP's fee ordinance lists a 'Commercial Photography, Film or Video Permit'. Read from a Wayback copy (2024-02-25) because lcfpd.org returns a Cloudflare 403 to scripted fetches. No drone-specific permit procedure found; the model-aircraft page (archived 2026-02-15) offers only the Van Patten Woods field. A 2014 staff memo, seen only as a search-result excerpt, said drones may not launch or land elsewhere in the preserves. source AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 3.7 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 3.3 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesOpens 6:30 am, before sunrise (~7:10). Sunrise at Grayslake is about 7:08-7:15 am CDT on Oct 19-25 2026 (my NOAA-formula estimate, +/-2 min); clocks fall back Nov 1 (sunrise then ~6:24 CST). Drive time is an OSRM estimate to the centroid. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h17.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.38 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.06 — mean 10 m wind in the 3 h before sunrise = 11.8 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.87 — overnight mid+high levels cloud = 30 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.9 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.4 °C vs afternoon dewpoint 13.7 °C → -4.3 °C; rain last 48 h = 17.5 mm; BUT dewpoint falls 6.7 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.3 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 87 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.053, ncep_nbm_conus 0.108, ecmwf_ifs025 0.073, icon_seamless 0.036 · spread 0.072

local	T	Td	T−Td	wind	low	mid	vis km
21:00	15.9	15.4	0.5	7.1	100	14	12.2
22:00	15.8	14.4	1.4	11.7	100	28	13.8
23:00	14.5	12.9	1.6	11.7	100	84	14.1
00:00	13.6	11.6	2.0	12.6	100	100	14.9
01:00	13.0	10.7	2.3	13.6	100	100	15.6
02:00	12.2	9.9	2.3	11.9	72	0	15.8
03:00	11.7	9.6	2.1	14.0	100	0	15.1
04:00	11.0	8.6	2.4	13.8	68	0	16.3
05:00	10.6	8.5	2.1	11.6	93	0	15.3
06:00	10.1	7.7	2.4	12.1	100	0	16.1
07:00	9.4	7.0	2.4	9.5	23	0	15.9
08:00	9.9	7.6	2.3	11.4	100	0	15.5
09:00	9.6	7.5	2.1	10.7	100	0	15.4
10:00	10.4	7.5	2.9	12.2	100	0	18.0
11:00	9.8	7.2	2.6	12.5	100	0	16.7

Almond Marsh Forest Preserve — 1 %, shallow ground fog

Where42.3303, -87.9857 · map Featuresmarsh, sedge meadow, savanna, wetland, oak woodland Lookmarsh and savanna fog from the ground at 6:30 opening; drone needs a Lake County Forest Preserves permit Access"Hours: 6:30 am-sunset, daily." (LCFP page, Wayback copy 2025-07-17); Visit Lake County: "Open daily 6:30 a.m.-sunset." But Visit Lake County says: "Parking, trails and facilities are not available at this site. Parking along Almond Road can be dangerous due to poor sight lines and fast moving traffic." Dronepermit — LCFP Regulations Governing the General Use of District Property (approved Jan 14 2020, amended Jan 17 2024), Sec. III.A: "No person shall use District Property for any of the following uses, unless the person has first obtained, and has physical possession of, a Permit allowing such use"; item (v): "use of any fuel-powered, air-propulsion, electric powered, radio-controlled, or cellular-controlled unmanned aerial Vehicle (commonly referred to as a \"drone\"), model or toy car, aircraft, boat or rocket, or any similar toy or model"; item (xx): "taking any still or motion pictures ... for commercial purposes or for use in commercial advertising". LCFP's fee ordinance lists a 'Commercial Photography, Film or Video Permit'. Read from a Wayback copy (2024-02-25) because lcfpd.org returns a Cloudflare 403 to scripted fetches. No drone-specific permit procedure found; the model-aircraft page (archived 2026-02-15) offers only the Van Patten Woods field. A 2014 staff memo, seen only as a search-result excerpt, said drones may not launch or land elsewhere in the preserves. source AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 3.6 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 3.2 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesBest cold-pool terrain on the list but no parking: roadside only. Nature-preserve portion may carry extra INPC rules (not researched). Sunrise at Grayslake is about 7:08-7:15 am CDT on Oct 19-25 2026 (my NOAA-formula estimate, +/-2 min); clocks fall back Nov 1 (sunrise then ~6:24 CST). Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h17.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.35 — min T−Td in the 3 h before sunrise = 2.2 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.05 — mean 10 m wind in the 3 h before sunrise = 12.0 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.89 — overnight mid+high levels cloud = 29 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.7 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.6 °C vs afternoon dewpoint 13.8 °C → -4.2 °C; rain last 48 h = 17.5 mm; BUT dewpoint falls 6.6 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.5 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 88 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.051, ncep_nbm_conus 0.107, ecmwf_ifs025 0.073, icon_seamless 0.035 · spread 0.072

local	T	Td	T−Td	wind	low	mid	vis km
21:00	16.5	16.0	0.5	8.2	100	9	12.2
22:00	16.0	14.4	1.6	11.9	100	41	14.1
23:00	14.7	13.1	1.6	11.9	100	64	14.1
00:00	13.7	11.8	1.9	12.6	88	100	15.1
01:00	13.1	10.8	2.3	13.6	100	100	15.6
02:00	12.3	9.9	2.4	12.0	100	0	15.9
03:00	11.8	9.7	2.1	14.2	100	0	15.1
04:00	11.2	8.6	2.6	13.9	66	0	16.5
05:00	10.7	8.5	2.2	11.7	91	0	15.5
06:00	10.3	7.9	2.4	12.4	100	0	16.0
07:00	9.6	7.2	2.4	10.0	27	0	16.2
08:00	9.9	7.7	2.2	11.0	100	0	15.7
09:00	9.7	7.5	2.2	10.7	100	0	15.6
10:00	10.4	7.5	2.9	11.4	100	0	17.8
11:00	9.9	7.1	2.8	12.2	100	0	16.9

Lakewood Forest Preserve — 1 %, shallow ground fog

Where42.2600, -88.0862 · map Featuresbog, marsh, wetland, pond, oak woodland Lookmarsh and savanna fog from the ground at 6:30 opening; drone needs a Lake County Forest Preserves permit AccessLCFP banner (archived pages): "Most preserves open 6:30 am-sunset." Lakewood's own page seen only as a search-result excerpt: 6:30 a.m. to sunset daily; portions closed for construction (not verified). Dronepermit — LCFP Regulations Governing the General Use of District Property (approved Jan 14 2020, amended Jan 17 2024), Sec. III.A: "No person shall use District Property for any of the following uses, unless the person has first obtained, and has physical possession of, a Permit allowing such use"; item (v): "use of any fuel-powered, air-propulsion, electric powered, radio-controlled, or cellular-controlled unmanned aerial Vehicle (commonly referred to as a \"drone\"), model or toy car, aircraft, boat or rocket, or any similar toy or model"; item (xx): "taking any still or motion pictures ... for commercial purposes or for use in commercial advertising". LCFP's fee ordinance lists a 'Commercial Photography, Film or Video Permit'. Read from a Wayback copy (2024-02-25) because lcfpd.org returns a Cloudflare 403 to scripted fetches. No drone-specific permit procedure found; the model-aircraft page (archived 2026-02-15) offers only the Van Patten Woods field. A 2014 staff memo, seen only as a search-result excerpt, said drones may not launch or land elsewhere in the preserves. source AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 9.7 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 9.3 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesAcreage conflicts in excerpts (2,835 vs 2,996). Wayback copy of the Lakewood page was not the preserve page, so hours/features rest on excerpts. Sunrise at Grayslake is about 7:08-7:15 am CDT on Oct 19-25 2026 (my NOAA-formula estimate, +/-2 min); clocks fall back Nov 1 (sunrise then ~6:24 CST). Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h12.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.40 — min T−Td in the 3 h before sunrise = 2.0 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.00 — mean 10 m wind in the 3 h before sunrise = 13.2 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.96 — overnight mid+high levels cloud = 23 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.9 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.39 — crossover: forecast night minimum 9.6 °C vs afternoon dewpoint 13.9 °C → -4.3 °C; rain last 48 h = 12.5 mm; BUT dewpoint falls 6.5 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.4 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 13 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 92 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.054, ncep_nbm_conus 0.104, ecmwf_ifs025 0.072, icon_seamless 0.038 · spread 0.066

local	T	Td	T−Td	wind	low	mid	vis km
21:00	17.2	16.8	0.4	8.6	100	11	12.2
22:00	15.8	14.5	1.3	12.9	100	17	13.5
23:00	14.5	12.9	1.6	13.1	100	33	14.0
00:00	13.6	11.8	1.8	13.7	100	100	14.7
01:00	12.9	10.8	2.1	14.8	96	91	15.5
02:00	12.3	10.8	1.5	13.3	100	0	13.9
03:00	11.5	9.3	2.2	16.4	100	0	15.8
04:00	10.9	8.8	2.1	15.2	100	0	15.5
05:00	10.6	8.6	2.0	13.2	74	0	15.4
06:00	10.0	7.8	2.2	13.4	100	0	15.8
07:00	9.6	7.4	2.2	10.8	47	0	15.9
08:00	9.5	7.7	1.8	12.1	100	0	15.2
09:00	9.4	7.2	2.2	12.4	100	0	15.7
10:00	10.0	7.5	2.5	12.4	100	0	17.1
11:00	9.6	7.1	2.5	13.2	100	0	16.9

Grant Woods Forest Preserve — 1 %, shallow ground fog

Where42.4115, -88.1181 · map Featuresmarsh, prairie, woodland, bog, pond Lookmarsh and savanna fog from the ground at 6:30 opening; drone needs a Lake County Forest Preserves permit Access"Hours: 6:30 am-sunset, daily." (LCFP page, Wayback copy 2025-09-14) Dronepermit — LCFP Regulations Governing the General Use of District Property (approved Jan 14 2020, amended Jan 17 2024), Sec. III.A: "No person shall use District Property for any of the following uses, unless the person has first obtained, and has physical possession of, a Permit allowing such use"; item (v): "use of any fuel-powered, air-propulsion, electric powered, radio-controlled, or cellular-controlled unmanned aerial Vehicle (commonly referred to as a \"drone\"), model or toy car, aircraft, boat or rocket, or any similar toy or model"; item (xx): "taking any still or motion pictures ... for commercial purposes or for use in commercial advertising". LCFP's fee ordinance lists a 'Commercial Photography, Film or Video Permit'. Read from a Wayback copy (2024-02-25) because lcfpd.org returns a Cloudflare 403 to scripted fetches. No drone-specific permit procedure found; the model-aircraft page (archived 2026-02-15) offers only the Van Patten Woods field. A 2014 staff memo, seen only as a search-result excerpt, said drones may not launch or land elsewhere in the preserves. source AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Not under the Class B shelf; Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 7.1 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 7.1 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. Beyond the Class B shelf at this point. NotesLCFP fall hunting or deer-management closures were not researched. Sunrise at Grayslake is about 7:08-7:15 am CDT on Oct 19-25 2026 (my NOAA-formula estimate, +/-2 min); clocks fall back Nov 1 (sunrise then ~6:24 CST). Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Rain 48 h23.1 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.40 — min T−Td in the 3 h before sunrise = 2.0 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.05 — mean 10 m wind in the 3 h before sunrise = 11.9 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.85 — overnight mid+high levels cloud = 32 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 6.0 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.2 °C vs afternoon dewpoint 13.8 °C → -4.6 °C; rain last 48 h = 23.1 mm; BUT dewpoint falls 6.7 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.2 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: precipitation around dawn (0.4 mm): drizzle/rain, not radiation fog
GATE ×0.6: low cloud deck 87 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.032, ncep_nbm_conus 0.107, ecmwf_ifs025 0.07, icon_seamless 0.036 · spread 0.075

local	T	Td	T−Td	wind	low	mid	vis km
21:00	15.7	15.1	0.6	5.8	100	8	12.2
22:00	15.5	14.1	1.4	11.6	100	43	13.7
23:00	14.3	12.7	1.6	11.5	100	100	14.2
00:00	13.3	11.3	2.0	12.2	100	100	14.7
01:00	12.8	10.4	2.4	14.0	89	94	16.1
02:00	12.2	9.9	2.3	11.5	90	0	15.5
03:00	11.5	9.2	2.3	14.6	100	2	15.9
04:00	10.9	8.6	2.3	14.1	57	0	15.6
05:00	10.4	8.4	2.0	12.2	67	0	15.2
06:00	10.0	7.6	2.4	12.5	100	0	16.2
07:00	9.2	7.1	2.1	8.9	51	0	15.2
08:00	9.7	7.6	2.1	11.0	100	0	15.3
09:00	9.4	7.2	2.2	11.0	100	0	15.4
10:00	10.2	7.1	3.1	13.5	100	0	18.1
11:00	9.7	7.0	2.7	12.6	100	0	17.0

Volo Bog State Natural Area — 1 %, shallow ground fog

Where42.3510, -88.1890 · map Featuresbog, marsh, prairie, woodland LookDeer archery hunting at Volo Bog is held in the fall (IDNR activities page); no drones for any aspect of hunting (520 ILCS 5/2.33(i)). Sunrise at Grayslake is about 7:08-7:15 am CDT on Oct 19-25 2026 (my NOAA-formula estimate, +/-2 min); clocks fall back Nov 1 (sunrise then ~6:24 CST). Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. AccessIDNR about page: "Site Hours: Gates open at 8:00 am 363 days a year-closed on Christmas and New Year's Days. Closing time is posted as one enters the parking lot ... plan to be back to the parking lot no later than 30 minutes before sunset." Gates open about 1 hr after sunrise. Dronepermit — 17 Ill. Adm. Code 110.160(i): it is unlawful "Except in cases of emergency, for any person to land or attempt to land any aircraft on Department-owned, -leased or -managed property without prior authorization for each landing or attempted landing from the Department." (verified at ilga.gov 2026-10-16). No site-specific drone page found. Wording says 'aircraft', not 'drone', and does not name the superintendent; treat as authorization required until the site office says otherwise. source AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Not under the Class B shelf; Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 10.9 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 10.5 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. Beyond the Class B shelf at this point. NotesDeer archery hunting at Volo Bog is held in the fall (IDNR activities page); no drones for any aspect of hunting (520 ILCS 5/2.33(i)). Sunrise at Grayslake is about 7:08-7:15 am CDT on Oct 19-25 2026 (my NOAA-formula estimate, +/-2 min); clocks fall back Nov 1 (sunrise then ~6:24 CST). Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:38, sunrise 07:07 at 101.5°, beams 07:21–08:20 Burn-off07:22–07:52 est.; HRRR clears n/a Rain 48 h19.3 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.40 — min T−Td in the 3 h before sunrise = 2.0 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.07 — mean 10 m wind in the 3 h before sunrise = 11.7 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.87 — overnight mid+high levels cloud = 30 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 6.1 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.2 °C vs afternoon dewpoint 13.8 °C → -4.6 °C; rain last 48 h = 19.3 mm; BUT dewpoint falls 6.8 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.2 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 86 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.054, ncep_nbm_conus 0.112, ecmwf_ifs025 0.075, icon_seamless 0.037 · spread 0.075

local	T	Td	T−Td	wind	low	mid	vis km
21:00	16.0	15.3	0.7	5.1	100	27	12.2
22:00	15.5	13.9	1.6	11.9	100	43	14.3
23:00	14.3	12.3	2.0	12.2	100	100	14.8
00:00	13.3	11.3	2.0	12.4	100	100	15.1
01:00	12.7	10.6	2.1	12.5	100	57	15.0
02:00	12.2	10.8	1.4	11.9	100	0	13.7
03:00	11.3	8.9	2.4	14.6	100	2	16.1
04:00	10.7	8.7	2.0	13.0	100	0	15.2
05:00	10.2	8.0	2.2	12.2	30	0	15.5
06:00	10.0	7.6	2.4	12.1	100	0	16.1
07:00	9.2	7.0	2.2	9.3	20	0	15.5
08:00	9.6	7.4	2.2	11.3	100	0	15.9
09:00	9.5	7.1	2.4	11.6	100	0	16.1
10:00	10.3	7.2	3.1	13.1	100	0	18.2
11:00	10.0	7.1	2.9	12.5	100	0	17.7

Chain O'Lakes State Park — 1 %, shallow ground fog

Where42.4670, -88.1890 · map Featureslake, river, marsh, backwater LookOUTSIDE the 20-minute target (OSRM 29.6 min); kept because the ticket asked for it. Dawn access is undecided: summer hours (gate open from 6:00 am) apply until 'the last weekend in October', which falls on Oct 24-25 or Oct 31-Nov 1 depending on reading, and then the park closes entirely for hunting. Next-week dates are at risk. Sunrise at Grayslake is about 7:08-7:15 am CDT on Oct 19-25 2026 (my NOAA-formula estimate, +/-2 min); clocks fall back Nov 1 (sunrise then ~6:24 CST). Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. AccessIDNR: "Summer hours 6:00 a.m. to 9:00 p.m. Winter hours: 8:00 a.m. to sunset. Summer hours take effect April 1st and terminate the last weekend in October when hunting begins and the entire park is closed for hunting. Hunting is by registration only. Entrance gates will be locked from 10:00 pm to 6:00 am during summer hours and sunset to 8 am during winter hours." Dronepermit — 17 Ill. Adm. Code 110.160(i): it is unlawful "Except in cases of emergency, for any person to land or attempt to land any aircraft on Department-owned, -leased or -managed property without prior authorization for each landing or attempted landing from the Department." (verified at ilga.gov 2026-10-16). No site-specific drone page found. Wording says 'aircraft', not 'drone', and does not name the superintendent; treat as authorization required until the site office says otherwise. source AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Not under the Class B shelf; Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; outside the O'Hare Mode C veil; surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 10.5 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 10.3 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. OUTSIDE the O'Hare Mode C veil here (32 nm from ORD). NotesOUTSIDE the 20-minute target (OSRM 29.6 min); kept because the ticket asked for it. Dawn access is undecided: summer hours (gate open from 6:00 am) apply until 'the last weekend in October', which falls on Oct 24-25 or Oct 31-Nov 1 depending on reading, and then the park closes entirely for hunting. Next-week dates are at risk. Sunrise at Grayslake is about 7:08-7:15 am CDT on Oct 19-25 2026 (my NOAA-formula estimate, +/-2 min); clocks fall back Nov 1 (sunrise then ~6:24 CST). Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:38, sunrise 07:07 at 101.5°, beams 07:21–08:20 Burn-off07:22–07:52 est.; HRRR clears n/a Riverriver water +9.1 °C warmer than the forecast dawn air (steam fog over open water needs roughly ≥5 °C and light wind; forecast wind 12 kt) Rain 48 h20.0 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.40 — min T−Td in the 3 h before sunrise = 2.0 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.06 — mean 10 m wind in the 3 h before sunrise = 11.8 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.98 — overnight mid+high levels cloud = 22 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 6.0 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 8.9 °C vs afternoon dewpoint 13.6 °C → -4.7 °C; rain last 48 h = 20.0 mm; BUT dewpoint falls 6.7 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.1 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 87 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.056, ncep_nbm_conus 0.107, ecmwf_ifs025 0.073, icon_seamless 0.062 · spread 0.051

local	T	Td	T−Td	wind	low	mid	vis km
21:00	15.4	14.8	0.6	4.1	89	10	12.2
22:00	15.2	13.6	1.6	12.5	100	28	13.9
23:00	13.9	12.1	1.8	12.3	100	100	14.3
00:00	13.1	11.3	1.8	12.1	100	100	14.6
01:00	12.7	10.1	2.6	14.8	88	2	16.5
02:00	11.8	9.5	2.3	11.6	100	0	15.7
03:00	11.3	8.9	2.4	14.1	100	0	16.1
04:00	10.6	8.5	2.1	13.4	40	0	15.4
05:00	10.2	8.1	2.1	12.2	77	0	15.4
06:00	9.9	7.3	2.6	12.4	87	0	16.5
07:00	8.9	6.9	2.0	9.3	74	0	15.1
08:00	9.5	7.4	2.1	11.1	100	0	15.5
09:00	9.3	7.2	2.1	11.8	100	0	15.3
10:00	9.8	6.9	2.9	13.2	100	0	17.4
11:00	9.6	6.9	2.7	13.0	100	0	17.3

Third Lake — 1 %, shallow ground fog

Where42.3739, -88.0109 · map Featureslake LookNo public-access page, boat launch or shoreline park was identified, so this is a view-from-elsewhere candidate only. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. AccessNone Droneunknown — No rule found; no managing agency identified. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 3.0 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 2.6 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesNo public-access page, boat launch or shoreline park was identified, so this is a view-from-elsewhere candidate only. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Riverriver water +8.7 °C warmer than the forecast dawn air (steam fog over open water needs roughly ≥5 °C and light wind; forecast wind 12 kt) Rain 48 h17.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.38 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.06 — mean 10 m wind in the 3 h before sunrise = 11.8 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.87 — overnight mid+high levels cloud = 30 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 6.0 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.3 °C vs afternoon dewpoint 13.7 °C → -4.4 °C; rain last 48 h = 17.5 mm; BUT dewpoint falls 6.8 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.3 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 87 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.053, ncep_nbm_conus 0.108, ecmwf_ifs025 0.073, icon_seamless 0.035 · spread 0.073

local	T	Td	T−Td	wind	low	mid	vis km
21:00	15.8	15.4	0.4	7.1	100	14	12.2
22:00	15.8	14.3	1.5	11.7	100	28	13.8
23:00	14.5	12.9	1.6	11.7	100	84	14.1
00:00	13.5	11.6	1.9	12.6	100	100	14.9
01:00	13.0	10.7	2.3	13.6	100	100	15.6
02:00	12.2	9.9	2.3	11.9	72	0	15.8
03:00	11.7	9.6	2.1	14.0	100	0	15.1
04:00	11.0	8.6	2.4	13.8	68	0	16.3
05:00	10.6	8.5	2.1	11.6	93	0	15.3
06:00	10.1	7.7	2.4	12.1	100	0	16.1
07:00	9.3	6.9	2.4	9.5	23	0	15.9
08:00	9.8	7.6	2.2	11.4	100	0	15.5
09:00	9.5	7.5	2.0	10.7	100	0	15.4
10:00	10.4	7.4	3.0	12.2	100	0	18.0
11:00	9.7	7.2	2.5	12.5	100	0	16.7

Gages Lake — 1 %, shallow ground fog

Where42.3535, -87.9820 · map Featureslake LookNo public-access page, boat launch or shoreline park was identified, so this is a view-from-elsewhere candidate only. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. AccessNone Droneunknown — No rule found; no managing agency identified. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 2.5 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 2.2 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesNo public-access page, boat launch or shoreline park was identified, so this is a view-from-elsewhere candidate only. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Riverriver water +8.5 °C warmer than the forecast dawn air (steam fog over open water needs roughly ≥5 °C and light wind; forecast wind 12 kt) Rain 48 h17.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.38 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.05 — mean 10 m wind in the 3 h before sunrise = 12.0 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.86 — overnight mid+high levels cloud = 31 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.7 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.5 °C vs afternoon dewpoint 13.7 °C → -4.2 °C; rain last 48 h = 17.5 mm; BUT dewpoint falls 6.6 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.4 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: low cloud deck 88 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.052, ncep_nbm_conus 0.108, ecmwf_ifs025 0.073, icon_seamless 0.035 · spread 0.073

local	T	Td	T−Td	wind	low	mid	vis km
21:00	16.0	15.5	0.5	7.7	100	10	12.2
22:00	15.9	14.2	1.7	11.9	100	39	14.0
23:00	14.6	13.0	1.6	11.9	100	89	14.0
00:00	13.7	11.7	2.0	12.8	100	100	15.0
01:00	13.1	11.0	2.1	13.5	100	100	15.4
02:00	12.1	9.8	2.3	12.0	61	0	15.8
03:00	11.7	10.0	1.7	13.8	100	0	14.7
04:00	11.2	8.6	2.6	13.9	83	0	16.5
05:00	10.7	8.6	2.1	11.9	100	0	15.4
06:00	10.2	7.8	2.4	12.3	100	0	16.0
07:00	9.5	7.1	2.4	10.0	23	0	16.1
08:00	9.8	7.6	2.2	10.9	100	0	15.6
09:00	9.6	7.6	2.0	11.2	100	0	15.4
10:00	10.4	7.4	3.0	11.7	100	0	17.7
11:00	9.8	7.2	2.6	12.8	100	0	16.7

Fourth Lake — 1 %, shallow ground fog

Where42.3913, -88.0334 · map Featureslake LookNo public-access page, boat launch or shoreline park was identified, so this is a view-from-elsewhere candidate only. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. AccessNone Droneunknown — No rule found; no managing agency identified. AirspaceFAA Class_Airspace + UAS Facility Map query 2026-10-16 at the geocoded point: Chicago Class B shelf above, floor 3,600 ft MSL (about 2,800 ft above ground); Chicago Class E5 (floor 700 ft AGL) and Illinois Class E5; inside the O'Hare Mode C veil (surface-10,000 ft MSL); surface is Class G. Not inside KUGN Class D or its Class E2 surface area (boundary about 3.6 nm away); no UAS Facility Map grid at the point (nearest KUGN grid about 3.3 nm, ceiling 400 ft), so no LAANC needed at 400 ft AGL or below. Not in any TFR (none in IL/WI/IN on the live list) or national-security restriction (FAA 99.7 list has no Lake County IL entry). Distances are from the geocoded point, +/-0.3 nm: re-check at the real launch point in B4UFLY/Aloft. NotesNo public-access page, boat launch or shoreline park was identified, so this is a view-from-elsewhere candidate only. Drive time is an OSRM public-router estimate from Grayslake centre (42.3447,-88.0418), not a measurement. Suncivil dawn 06:37, sunrise 07:06 at 101.5°, beams 07:20–08:19 Burn-off07:21–07:51 est.; HRRR clears n/a Riverriver water +8.5 °C warmer than the forecast dawn air (steam fog over open water needs roughly ≥5 °C and light wind; forecast wind 12 kt) Rain 48 h17.5 mm (Open-Meteo ICON assimilated past days (model analysis, not a gauge))

Factors (HRRR):

dewpoint depression: 0.37 — min T−Td in the 3 h before sunrise = 2.1 °C (≤1 °C strongly favours fog, >3 °C rarely fogs)
wind: 0.07 — mean 10 m wind in the 3 h before sunrise = 11.6 kt (2–5 kt ideal; calm gives only shallow fog; >8 kt mixes it out)
sky: 0.85 — overnight mid+high levels cloud = 31 % (clear sky lets the ground radiate and cool)
cooling: 0.40 — temperature fall 18:00 → sunrise = 5.8 °C; part of this is cold advection, not radiation (discounted)
moisture: 0.40 — crossover: forecast night minimum 9.5 °C vs afternoon dewpoint 13.8 °C → -4.3 °C; rain last 48 h = 17.5 mm; BUT dewpoint falls 6.7 °C by dawn — drier air moving in, crossover rule discounted
model signal: 0.10 — model's own visibility minimum before sunrise = 15.5 km (0 h ≤ 1 km overnight)
GATE ×0.25: wind 12 kt: too much mixing for radiation fog
GATE ×0.6: precipitation around dawn (0.4 mm): drizzle/rain, not radiation fog
GATE ×0.6: low cloud deck 88 % overnight with good visibility: stratus, not fog

per-model blend: gfs_hrrr 0.031, ncep_nbm_conus 0.108, ecmwf_ifs025 0.07, icon_seamless 0.036 · spread 0.077

local	T	Td	T−Td	wind	low	mid	vis km
21:00	15.8	15.3	0.5	5.9	100	11	12.2
22:00	15.8	14.4	1.4	11.5	100	38	13.7
23:00	14.5	12.9	1.6	11.5	100	92	14.1
00:00	13.6	11.6	2.0	12.4	100	100	14.9
01:00	13.1	11.0	2.1	13.1	100	100	15.5
02:00	12.2	9.9	2.3	11.6	74	0	15.8
03:00	11.8	9.9	1.9	13.1	100	0	14.9
04:00	11.2	8.6	2.6	13.2	74	0	16.4
05:00	10.8	8.7	2.1	11.6	92	0	15.5
06:00	10.3	7.9	2.4	11.9	100	0	16.2
07:00	9.5	7.1	2.4	9.5	31	0	16.0
08:00	9.9	7.7	2.2	10.9	100	0	15.6
09:00	9.7	7.8	1.9	10.8	100	0	15.0
10:00	10.5	7.5	3.0	12.4	100	0	18.0
11:00	9.8	7.2	2.6	12.4	100	0	16.7

Independent checks

NBM bulletin for KUGN (cycle 2026-10-16T04:00:00+00:00, NOAA's own blend; P = probability)

local	T °F	Td °F	wind	sky %	vis mi	P(vis<1 mi)	P(vis<3 mi)	ceiling
03:00	49	48	15	87	10.0	3 %	4 %	13
04:00	48	47	14	81	10.0	3 %	4 %	13
05:00	47	46	14	79	10.0	3 %	4 %	13
06:00	46	45	13	71	10.0	2 %	5 %	15
07:00	46	44	13	70	10.0	2 %	6 %	15
08:00	48	45	13	67	9.0	3 %	9 %	13
09:00	51	46	13	88	9.0	4 %	11 %	13

HRRR vertical profile at KUGN (run 2026-10-15 19:00 local, Penn State BUFKIT; saturated depth = height to which T−Td ≤ 1 °C)

local	inversion (80 m − 10 m)	lowest levels (m AGL: T / Td)
03:00	-0.6 °C	11: 12.3/10.0 · 36: 12.1/9.8 · 82: 11.7/9.6 · 161: 11.0/9.4
04:00	-0.6 °C	11: 11.4/9.2 · 36: 11.2/9.0 · 82: 10.8/8.8 · 161: 10.1/8.5
05:00	-0.6 °C	11: 11.1/8.5 · 36: 10.9/8.3 · 82: 10.5/8.1 · 160: 9.8/7.7
06:00	-0.5 °C	10: 10.7/8.1 · 35: 10.6/7.9 · 81: 10.2/7.7 · 160: 9.5/7.4
07:00	-0.4 °C	11: 10.3/7.7 · 35: 10.2/7.4 · 82: 9.9/7.2 · 160: 9.3/6.9
08:00	-0.6 °C	11: 10.2/8.3 · 35: 10.0/8.1 · 81: 9.6/8.0 · 160: 8.9/7.7
09:00	-0.6 °C	11: 10.5/7.5 · 36: 10.3/7.2 · 82: 9.9/7.0 · 161: 9.1/6.8

Right now at KUGN
SPECI KUGN 160504Z AUTO 27010G22KT 10SM SCT014 BKN023 OVC030 14/12 A2978 RMK AO2 T01390122
Observed T−Td 1.7 °C vs HRRR for this hour 1.9 °C — a model running dry or moist shows here.

Rivers (USGS)

DES PLAINES RIVER AT RUSSELL, IL: stage 4.40 ft
DES PLAINES RIVER NEAR GURNEE, IL: stage 3.11 ft
FOX RIVER NEAR MCHENRY, IL: stage 4.01 ft, water 18.0 °C

NWS Chicago forecast discussion 2026-10-15T23:37:00+00:00

The primary low-pressure system will track directly over northern Illinois early this evening, then deepen as it shifts northeast into lower Michigan tonight. Expect a brief period of lower ceilings and reduced visibility for a few hours as the low moves overhead. Conditions will improve rapidly later tonight following a sharp cold front. In its wake, northwest winds will become gusty (3035 mph) overnight, while strong cold air advection drops temperatures into the 40s to low 50s by early Friday morning. Breezy conditions (gusts of 35 to 40 mph) will persist through Friday due to strong pressure rises behind the departing low and ahead of a 1035+ mb surface high building in from the Plains. Even stronger northerly winds (~45 mph) are projected over southern Lake Michigan Friday afternoon and evening. Onshore flow will push some of these higher winds inland across far northern Porter County, Indiana, where a Wind Advisory is in effect from 1:00 PM to 10:00 PM CDT Friday.

Were you out there?

One tap at dawn. This is the only truth the tool gets from the field; the airport sensor cannot see a river bottom.

Verification so far

morning	run	forecast	grade	airport min vis	airport fog?	field report	cam
2026-10-16	evening	1 %	F	—	pending	—	frame frame frame
2026-10-16	predawn	1 %	F	—	pending	—	frame frame frame

Honesty notes

Probability is a blend of HRRR, NBM, ECMWF and ICON point forecasts (model output). Type, depth and burn-off are rules of thumb (estimates) unless marked 'model profile'.
Calibrated on 329 airport mornings (2026-08-21..2026-10-15 at GYY, IKK, JOT, LOT, PNT, RZL). Airports fog less than river bottoms; read site rows as a ranking.
Backtest, in-sample (329 airport mornings, 34 fog cases on 13 distinct mornings): forecasts in each band verified as 0.0–0.1: fog 4 % of 191; 0.1–0.2: fog 16 % of 81; 0.2–0.3: fog 15 % of 46; 0.3–0.4: fog 50 % of 10. Ranking skill AUC 0.761; held-out-station Brier 0.085 vs climatology 0.093.
Drone law: 14 CFR 107.51 needs 3 statute miles flight visibility and 500 ft below cloud. Fog is cloud on the ground, so launching through a deck is outside the rule; your call, not this tool's.
Sources and fetch times for every number: site/grayslake/data/2026-10-16-*.json.

dashboard · 7-day outlook · raw json