Severe Thunderstorm Warning for Monroe, IL Until 11:30 PM CDT

Residents of Monroe County, Illinois, are advised to seek immediate shelter due to a Severe Thunderstorm Warning issued by the National Weather Service (NWS) St. Louis, MO. The warning is in effect from 11:16 PM CDT until 11:30 PM CDT tonight, September 20, 2026.

At 11:16 PM CDT, NWS radar indicated a severe thunderstorm near Valmeyer, or near Waterloo, moving northeast at 25 mph. This storm is capable of producing damaging winds up to 60 mph and quarter-sized hail. Potential impacts include hail damage to vehicles and wind damage to roofs, siding, and trees.

Locations impacted include Harrisonville, Chalfin Bridge, Valmeyer, Monroe City, Madonnaville, Fountain, Maeystown, Foster Pond, Wartburg, Burksville, New Hanover, Waterloo, Columbia, and Illinois Caverns State Natural Area.

The NWS instructs individuals to seek shelter inside a well-built structure and stay away from windows during this severe weather event.