Flood Warning — Grundy County, Illinois
Flooding is occurring or imminent along rivers, streams, or low-lying areas.
Current Status
🌊 Active: Flood Warning
Flood Warning issued August 10 at 2:32AM CDT until August 10 at 7:00AM CDT by NWS Chicago IL
* WHAT...Flooding caused by excessive rainfall is expected. * WHERE...Northeastern Livingston County in central Illinois... East Central La Salle County in north central Illinois... Southern Grundy County in northeastern Illinois... * WHEN...Until 700 AM CDT. * IMPACTS...Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas. Slow moving or standing water may continue. High water likely may recede slowly from flooded areas. * ADDITIONAL DETAILS... - At 228 AM CDT, Doppler radar indicated that heavy rainfall had moved out of the area. Rainfall amounts of 2 to 3 inches occurred across the area, with rainfall in excess of 4 inches observed near Dwight. Water will be slow to recede from fields, yards, and poor drainage areas. Some streams may continue to rise due to earlier rainfall as runoff moves downstream. - Some locations that will experience flooding include... Ottawa, Streator, Dwight, Gardner, Mazon, Grand Ridge, South Wilmington, Ra
Effective August 10, 2026 at 3:32 AM ET · Expires August 10, 2026 at 8:00 AM ET
Event Details
Event Type
Flood Warning
Severity
severe
Issued By
NWS Chicago IL
Expires
August 10, 2026 at 8:00 AM ET
Last Checked
1 minute ago
What To Do
📋 Official NWS Guidance
A Flood Warning means flooding is imminent or may already be occurring. Persons along rivers, creeks, and other waterways should take immediate precautions to protect life and property. Be especially cautious at night when it is harder to recognize the dangers of flooding.
Also In Effect For
This same Flood Warning also covers:
Other Active Alerts in Illinois
Flood Advisory
Flood Advisory
Flood Advisory
Flood Advisory
Flood Advisory
Flood Advisory
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Frequently Asked Questions
What does a Flood Warning mean for Grundy County, Illinois?
Flooding is occurring or imminent along rivers, streams, or low-lying areas.
Is this Flood Warning currently active?
Yes — this alert is active as of our last check (1 minute ago). It's set to expire August 10, 2026 at 8:00 AM ET.
How do I get notified about Flood Warning alerts for Grundy County?
Download StormCast free on Google Play and set Grundy 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 Flood Warning is also in effect for La Salle County, Livingston County.