Red Flag Warning Issued for Chicago Metro and Northeastern Illinois Through Wednesday Evening

Alert Details

The National Weather Service in Chicago has issued a Red Flag Warning for northeastern Illinois, effective until 8 PM CST this evening, February 18, 2026. The alert was expanded this morning to include the Chicago metropolitan area as conditions turn increasingly supportive of rapid brush fire spread.

Affected Areas

The warning specifically impacts the following counties in Illinois:

• Lake
• DuPage
• Cook
• Will
• Kankakee

What You Should Do

Outdoor burning is not recommended under these conditions. A Red Flag Warning signifies that critical fire weather conditions are either occurring now or are imminent. Residents should be aware that any fire that develops will catch and spread quickly. A combination of strong winds, low relative humidity, and warm temperatures can contribute to extreme fire behavior.

Expected Conditions

While the region saw rainfall between 0.05 and 0.15 of an inch last night, the combination of warm and windy weather will cause fine fuels to dry out by early afternoon.

• Winds: Southwest winds of 20 to 30 mph, with gusts reaching up to 45 mph.
• Relative Humidity: Levels dropping as low as 15 to 20 percent.
• Fire Behavior: Conditions are supportive of rapid fire spread due to the drying of fine fuels.

Timeline

The Red Flag Warning is currently in effect and is scheduled to expire at 8 PM CST this evening, February 18.