Weather Warnings for Illinois

Issued by the National Weather Service

Current watches, warnings, and advisories for Illinois
Alerts Updated: August 13, 2026, 12:00 am  UTC


Severe Thunderstorm Warning issued August 12 at 6:43PM CDT until August 12 at 7:45PM CDT by NWS St Louis MO

Summary: SVRLSX The National Weather Service in St Louis has issued a * Severe Thunderstorm Warning for... Central Randolph County in southwestern Illinois... Northeastern Sainte Genevieve County in southeastern Missouri... * Until 745 PM CDT. * At 643 PM CDT, a severe thunderstorm was located near Ste. Genevieve, moving southeast at 15 mph. HAZARD...60 mph wind gusts and quarter size hail. SOURCE...Radar indicated. IMPACT...Hail damage to vehicles is expected. Expect wind damage to roofs, siding, and trees. * Locations impacted include... Prairie Du Rocher, Ruma, Modoc, Kellogg, Evansville, Ste. Genevieve, Roots, Walsh, Ellis Grove, New Palestine, Blair, Kaskaskia, Chester, St. Mary and Bremen. This includes the following State Parks... Randolph County State Recreation Area and Felix Valle House State Park. This includes Interstate 55 in Missouri between exits 141 and 143.
Severity:  Severe    Effective:  August 12, 2026, 6:43 pm      Expires:  August 12, 2026, 7:45 pm
Area:  Randolph, IL; Ste. Genevieve, MO


Special Weather Statement issued August 12 at 6:42PM CDT by NWS Quad Cities IA IL

Summary: Conditions are favorable for the development of funnel clouds, and possibly brief, weak tornadoes. At 545 PM, there was a funnel cloud reported near Ainsworth, Iowa. The National Weather Service will continue to closely monitor the situation, and may issue a Tornado Warning if the threat increases. If you see a funnel cloud or tornado, seek shelter indoors and then contact your local law enforcement agency for relay to the National Weather Service.
Severity:  Moderate    Effective:  August 12, 2026, 6:42 pm      Expires:  August 12, 2026, 9:00 pm
Area:  Keokuk; Washington; Louisa; Jefferson; Henry; Des Moines; Van Buren; Lee; Mercer; Henderson; Warren


Flood Advisory issued August 12 at 6:12PM CDT until August 12 at 9:15PM CDT by NWS Paducah KY

Summary: * WHAT...Urban area and small stream flooding caused by excessive rainfall is expected. * WHERE...Northern Franklin County in south central Illinois... Hamilton County in south central Illinois... Southern Jefferson County in south central Illinois... * WHEN...Until 915 PM CDT. * IMPACTS...Minor flooding in low-lying and poor drainage areas. * ADDITIONAL DETAILS... - At 612 PM CDT, Doppler radar indicated heavy rain due to thunderstorms. This will cause urban and small stream flooding. Between 1 and 2 inches of rain have fallen. - Additional rainfall amounts up to 1 inch are expected over the area. This additional rain will result in minor flooding. - Some locations that will experience flooding include... Mcleansboro, Rend Lake Area, Sesser, Ina, Dahlgren, Waltonville, Bonnie, Belle Rive, Ewing, Nason, Broughton, Macedonia and Belle Prairie City. - http://www.weather.gov/safety/flood
Severity:  Minor    Effective:  August 12, 2026, 6:12 pm      Expires:  August 12, 2026, 9:15 pm
Area:  Franklin, IL; Hamilton, IL; Jefferson, IL


Flood Warning issued August 12 at 2:48PM CDT until August 13 at 7:00PM CDT by NWS Chicago IL

Summary: ...The Flood Warning is extended for the following rivers in Illinois... Thorn Creek at Thornton affecting Cook County. For the Thorn Creek...including Thornton...Minor flooding is forecast. * WHAT...Minor flooding is occurring and minor flooding is forecast. * WHERE...Thorn Creek from Near Glenwood downstream to confluence with Little Calumet River, including the Thornton gauge. * WHEN...Until Thursday evening. * IMPACTS...At 11.0 feet, 187th Street threatened in Glenwood. * ADDITIONAL DETAILS... - At 2:30 PM CDT Wednesday the stage was 9.6 feet. - Recent Activity...The maximum river stage in the 24 hours ending at 2:30 PM CDT Wednesday was 10.6 feet. - Forecast...The river is expected to rise to a crest around 10 feet tonight. It will then fall below flood stage tomorrow afternoon. - Flood stage is 9.0 feet. - http://www.weather.gov/safety/flood
Severity:  Severe    Effective:  August 12, 2026, 2:48 pm      Expires:  August 13, 2026, 9:00 am
Area:  Cook, IL


Heat Advisory issued August 12 at 1:20PM CDT until August 12 at 8:00PM CDT by NWS Lincoln IL

Summary: * WHAT...Heat index values up to 103. * WHERE...Clay, Crawford, Effingham, Jasper, Lawrence, and Richland Counties. * WHEN...Until 8 PM CDT this evening. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses.
Severity:  Moderate    Effective:  August 12, 2026, 1:20 pm      Expires:  August 12, 2026, 8:00 pm
Area:  Effingham; Jasper; Crawford; Clay; Richland; Lawrence


Extreme Heat Warning issued August 12 at 1:14PM CDT until August 15 at 9:00PM CDT by NWS St Louis MO

Summary: * WHAT...Dangerously hot conditions with heat index values up to 111. * WHERE...Portions of south central and southwest Illinois and central and east central Missouri. * WHEN...Until 9 PM CDT Saturday. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events.
Severity:  Severe    Effective:  August 12, 2026, 1:14 pm      Expires:  August 13, 2026, 4:15 am
Area:  Clinton; Washington; Randolph; Madison; St. Clair; Monroe; Boone; Moniteau; Cole; Osage; Callaway; Montgomery; Gasconade; Warren; St. Charles; Franklin; St. Louis; St. Louis City; Jefferson


Heat Advisory issued August 12 at 1:14PM CDT until August 15 at 9:00PM CDT by NWS St Louis MO

Summary: * WHAT...Heat index values up to 109. * WHERE...Portions of south central and southwest Illinois and central, east central, and northeast Missouri. * WHEN...Until 9 PM CDT Saturday. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses.
Severity:  Moderate    Effective:  August 12, 2026, 1:14 pm      Expires:  August 13, 2026, 4:15 am
Area:  Greene; Macoupin; Montgomery; Bond; Fayette; Marion; Calhoun; Jersey; Monroe; Ralls; Pike; Audrain; Lincoln


Heat Advisory issued August 12 at 1:11PM CDT until August 13 at 11:00AM CDT by NWS Paducah KY

Summary: * WHAT...For the Heat Advisory, heat index values up to 107. For the Extreme Heat Warning, dangerously hot conditions with heat index values up to 110 expected. * WHERE...Portions of southern Illinois, southwest Indiana, western Kentucky, and southeast Missouri. * WHEN...For the Heat Advisory, until 11 AM CDT /noon EDT/ Thursday. For the Extreme Heat Warning, from 11 AM CDT /noon EDT/ Thursday to 8 PM CDT /9 PM EDT/ Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events.
Severity:  Moderate    Effective:  August 12, 2026, 1:11 pm      Expires:  August 13, 2026, 4:15 am
Area:  Jefferson; Wayne; Edwards; Wabash; Franklin; Hamilton; White; Jackson; Williamson; Saline; Gallatin; Union; Johnson; Pope; Hardin; Alexander; Pulaski; Massac; Gibson; Pike; Posey; Vanderburgh; Warrick; Spencer; Fulton; Hickman; Carlisle; Ballard; McCracken; Graves; Livingston; Marshall; Calloway; Crittenden; Lyon; Trigg; Caldwell; Union; Webster; Hopkins; Christian; Henderson; Daviess; McLean; Muhlenberg; Todd; Perry; Bollinger; Cape Girardeau; Wayne; Carter; Ripley; Butler; Stoddard; Scott; Mississippi; New Madrid


Extreme Heat Warning issued August 12 at 1:11PM CDT until August 16 at 8:00PM CDT by NWS Paducah KY

Summary: * WHAT...For the Heat Advisory, heat index values up to 107. For the Extreme Heat Warning, dangerously hot conditions with heat index values up to 110 expected. * WHERE...Portions of southern Illinois, southwest Indiana, western Kentucky, and southeast Missouri. * WHEN...For the Heat Advisory, until 11 AM CDT /noon EDT/ Thursday. For the Extreme Heat Warning, from 11 AM CDT /noon EDT/ Thursday to 8 PM CDT /9 PM EDT/ Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events.
Severity:  Severe    Effective:  August 12, 2026, 1:11 pm      Expires:  August 13, 2026, 4:15 am
Area:  Jefferson; Wayne; Edwards; Wabash; Franklin; Hamilton; White; Jackson; Williamson; Saline; Gallatin; Union; Johnson; Pope; Hardin; Alexander; Pulaski; Massac; Gibson; Pike; Posey; Vanderburgh; Warrick; Spencer; Fulton; Hickman; Carlisle; Ballard; McCracken; Graves; Livingston; Marshall; Calloway; Crittenden; Lyon; Trigg; Caldwell; Union; Webster; Hopkins; Christian; Henderson; Daviess; McLean; Muhlenberg; Todd; Perry; Bollinger; Cape Girardeau; Wayne; Carter; Ripley; Butler; Stoddard; Scott; Mississippi; New Madrid


Extreme Heat Warning issued August 12 at 1:11PM CDT until August 16 at 8:00PM CDT by NWS Paducah KY

Summary: * WHAT...Dangerously hot conditions with heat index values up to 112. * WHERE...Perry County Illinois. * WHEN...Until 8 PM CDT Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events.
Severity:  Severe    Effective:  August 12, 2026, 1:11 pm      Expires:  August 13, 2026, 4:15 am
Area:  Perry