CHICAGO | An active Flash Flood Warning is in effect for Chicago and Cook County. CGN News is publishing this alert because official National Weather Service alert data includes one or more CGN coverage areas: Cook County, Illinois.
What is active now
The primary active alert is Flash Flood Warning with NWS severity listed as Severe, urgency listed as Immediate and certainty listed as Likely.
The alert became effective 24 June 2026 at 9:37 PM EDT. The current listed expiration or ending time is 25 June 2026 at 12:45 AM EDT. Readers should rely on the latest county-specific National Weather Service alert before making safety decisions.
Current official alerts
Flash Flood Warning: NWS lists the affected area as Cook, IL; Lake, IN. Current listed expiration or ending time: 25 June 2026 at 12:45 AM EDT.
Severe Thunderstorm Watch: NWS lists the affected area as Cook, IL; Grundy, IL; Kankakee, IL; La Salle, IL; Livingston, IL; Will, IL; Lake, IN; Porter, IN. Current listed expiration or ending time: 24 June 2026 at 11:00 PM EDT.
Flood Advisory: NWS lists the affected area as Cook, IL; Lake, IN. Current listed expiration or ending time: 25 June 2026 at 12:00 AM EDT.
Flood Advisory: NWS lists the affected area as Cook, IL; Kane, IL. Current listed expiration or ending time: 24 June 2026 at 10:30 PM EDT.
Flood Advisory: NWS lists the affected area as Cook, IL; DuPage, IL; Will, IL. Current listed expiration or ending time: 24 June 2026 at 11:30 PM EDT.
Coverage area
This CGN alert covers Cook County, Illinois. Nearby communities may experience different conditions, and warnings can change quickly.
Safety
Do not drive through floodwater. Water can be deeper than it appears, and roads may be damaged beneath the surface. Keep children and pets away from flooded creeks, ditches, drainage areas and riverbanks.
Official instruction
A Flash Flood Warning means rapid-onset flooding is imminent or may already be occurring. Persons along creeks, drainage ditches, and other waterways should take immediate precautions to protect life and property.
This alert should be updated if the National Weather Service issues, cancels, extends or replaces the active alert. Do not rely on this article alone for emergency decisions. Keep wireless emergency alerts enabled and monitor official NWS, NOAA, local emergency management and trusted local broadcast sources.
Additional Reporting By: National Weather Service; NOAA; National Weather Service Chicago