Illinois Flood Warning | Effective 04/18/2026 17:57

Headline: 
Flood Warning issued April 18 at 7:57PM CDT until April 20 at 11:30PM CDT by NWS Chicago IL
Event: 
Flood Warning
Urgency: 
Expected
Effective: 
April 18, 2026 - 5:57pm
Expires: 
April 19, 2026 - 12:00pm
Description: 
...Forecast flooding changed from Minor to Moderate severity and increased in duration for the following rivers in Illinois... Kishwaukee River at Belvidere affecting Boone and Winnebago Counties. * WHAT...Minor flooding is occurring and moderate flooding is forecasted to occur. * WHERE...Kishwaukee River from County Line Road downstream to confluence with South Branch Kishwaukee River, including the Belvidere gauge. * WHEN...Until late Monday evening. * IMPACTS...At 10.0 feet, Trails in Spencer Park threatened. Parking lots threatened in Belvidere Park. * ADDITIONAL DETAILS... - At 7:30 PM CDT Saturday the stage was 9.8 feet. - Forecast...The river is expected to rise to a crest near 10.0 feet (Moderate Stage) tomorrow morning. It is then expected to fall below flood stage at some point on Monday. - Flood stage is 9.0 feet. - http://www.weather.gov/safety/flood
Instruction: 
A Flood Warning means water levels above flood stage are imminent or may already be occurring. Persons along rivers and streams in the warned area should take immediate precautions to protect life and property. These forecasts are based on observed precipitation as well as forecast precipitation 24 hours into the future. Changes to the rainfall forecast, or any additional rainfall after 24 hours, may cause changes to these river forecasts. Additional information is available at www.weather.gov. The next statement will be issued by Sunday afternoon.
Area Description: 
Boone, IL; Winnebago, IL
Forcast Office: 
NWS Chicago IL