Moderate Extreme Weather ● Active
Dense Fog Advisory issued October 20 at 3:42AM CDT until October 20 at 9:00AM CDT by NWS Chicago IL, United States of America
Loading live data… · Marker positions are approximate; severity is labelled in each popup. Sources: USGS, GDACS, NASA EONET, NOAA/NWS, EMSC.
* WHAT...Areas of dense fog reducing visibility locally near zero.
* WHERE...Lake IL and Northern Cook Counties.
* WHEN...Until 9 AM CDT this morning.
* IMPACTS...Low visibility could make driving conditions hazardous.
* ADDITIONAL DETAILS...Due to the patchy nature of the dense fog,
motorists should be prepared to encounter sudden, dramatic drops in
visibility to near zero.
Measurements
| Coordinates | 39.9645, -100.8105 |
|---|---|
| Region | Lake; Northern Cook |
| Location Precision | country |
| Issuing Authority | United States of America — us-noaa-nws-en |
| Cap Urgency | Expected |
| Cap Certainty | Likely |
| Cap Expires | 2026-10-20T09:00:00-05:00 |
Official source
Warnings courtesy of the issuing national meteorological service, via the WMO Alert Hub.
This is an official warning issued by the authority named above. Follow its instructions and those of your local emergency services.
Severity as published by WMO Alert Hub (national weather services).
View original reportThis event as JSON · API and licence
Source updated 54 minutes ago (Oct 20, 2026 08:43 UTC) · we last heard from WMO Alert Hub (national weather services) 23 seconds ago
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About this location
The agency did not publish coordinates for this warning. The pin is the centre of the country, not the location of the event — read the area name, not the map, for where it applies.
Area as the agency stated it: Lake; Northern Cook
Official authorities in United States
If you are there, these are the bodies whose instructions apply. This site is not an emergency service and does not issue warnings.
More for United States →What to do
Follow the instructions issued by WMO Alert Hub (national weather services) and your local emergency services. The guidance below is background.
When thunder roars, go indoors — lightning risk outdoors, in vehicles, and first aid for strike victims.
Open Lightning Safety Guide →Earlier extreme weather events in United States
Severe and extreme events of the same kind, before this one. Listed for scale, not because they are connected to it.
Nearby & related events
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