Severe Thunderstorm Warning — St. Clair County, Illinois
A thunderstorm capable of producing damaging winds of 58+ mph and/or 1-inch hail has been detected.
Current Status
⛈️ Active: Severe Thunderstorm Warning
Severe Thunderstorm Warning issued August 16 at 9:44PM CDT until August 16 at 10:00PM CDT by NWS St Louis MO
At 944 PM CDT, a severe thunderstorm was located near Cahokia, or near Cahokia Parks Airport, moving east at 30 mph. HAZARD...60 mph wind gusts and small hail. SOURCE...Radar indicated. IMPACT...Expect damage to roofs, siding, and trees. Locations impacted include... Clayton, University City, Brentwood, Webster Groves, St. Louis, Richmond Heights, Maplewood, Jennings, Bellefontaine Neighbors, Granite City, Cahokia, East St. Louis, Columbia, Collinsville, Glen Carbon, Belleville, Fairview Heights and Maryville. This includes the following State Parks... Frank Holten State Park, Horseshoe Lake State Park and Scott Joplin Historic Site. This includes Interstate 64 in Illinois near exit 9.
Effective August 16, 2026 at 10:44 PM ET · Expires August 16, 2026 at 11:00 PM ET
Event Details
Event Type
Severe Thunderstorm Warning
Severity
severe
Issued By
NWS St Louis MO
Expires
August 16, 2026 at 11:00 PM ET
Last Checked
3 hours ago
What To Do
📋 Official NWS Guidance
Seek shelter inside a well-built structure and stay away from windows. This storm is capable of producing damaging winds. Continuous cloud to ground lightning is occurring with this storm. Lightning is one of nature's leading killers. Remember, if you can hear thunder, you are close enough to be struck by lightning.
Also In Effect For
This same Severe Thunderstorm Warning also covers:
Other Active Alerts in Illinois
Flood Advisory
Flood Advisory
Flood Warning
Flood Warning
Flood Warning
Flood Warning
Get Severe Thunderstorm Warning Alerts for St. Clair County
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Frequently Asked Questions
What does a Severe Thunderstorm Warning mean for St. Clair County, Illinois?
A thunderstorm capable of producing damaging winds of 58+ mph and/or 1-inch hail has been detected.
Is this Severe Thunderstorm Warning currently active?
Yes — this alert is active as of our last check (3 hours ago). It's set to expire August 16, 2026 at 11:00 PM ET.
How do I get notified about Severe Thunderstorm Warning alerts for St. Clair County?
Download StormCast free on Google Play and set St. Clair County, Illinois as one of your monitored locations. StormCast checks the NWS feed continuously and pushes alerts like this directly to your phone — even with the screen off.
What other areas does this alert cover?
This same Severe Thunderstorm Warning is also in effect for St. Louis City County, St. Louis County.