Flood Warning Issued for Cook County, IL
If you are in immediate danger, call emergency services now.
For real-time, official alerts and instructions for your exact location, check weather.gov (US), weather.gc.ca (Canada), the Met Office (UK), or the Bureau of Meteorology (Australia) as applicable. This article is a data summary, not a substitute for the issuing agency's live warning.
Areazine synthesizes this NWS weather alert directly from NOAA's official public data feed. See our methodology for full source attribution and refresh cadence.
NWS Chicago has issued a Flood Warning for Thorn Creek at Thornton in Cook County until Sunday morning.
Read this weather record in 30 seconds
- Record type
- Flood Warning
- Affected area
- Cook County, Illinois
- Issued
- August 1, 2026
- Issuing authority
- NWS Chicago IL
Flood notices turn on location and timing. Treat the named area as this record's scope; do not assume nearby counties, parishes, or waterways were included.
Record status: publication date is recent, but current status is not stored on this page. Check the issuing agency's live warning service before acting because warnings can be updated, narrowed, or cancelled.
Alert Details
A Flood Warning has been issued by the National Weather Service Chicago IL. The alert is effective from August 1 at 2:44 PM CDT until August 2 at 9:00 AM CDT.
Affected Areas
Cook County, Illinois. Specifically, Thorn Creek from near Glenwood downstream to the confluence with the Little Calumet River, including the Thornton gauge.
What You Should Do
Persons along rivers and streams in the warned area should take immediate precautions to protect life and property.
Expected Conditions
Minor flooding is forecast. At 2:15 PM CDT on August 1 the stage was 8.6 feet. The river is expected to rise above flood stage (9.0 feet) late this afternoon to a crest of 10.0 feet this evening, then fall below flood stage late tonight. At 9.0 feet, water begins to be diverted through the Thorn Creek Diversion Tunnel.
Timeline
The warning is in effect until Sunday morning, August 2 at 9:00 AM CDT.
Original source: NOAA Official Notice ↗
Related Weather Alerts
All Weather Alerts →Frequently Asked Questions
Common questions about this NWS weather alert.