Chicago, Illinois – A dangerous stretch of heat is set to grip Illinois, with heat index values soaring as high as 115 degrees from Wednesday morning through Thursday evening. The National Weather Service warns that life-threatening heat will impact both northern and central regions, including Chicago, where overnight relief may be minimal.
According to the National Weather Service in Chicago, an Extreme Heat Watch will be in effect from 10 a.m. Wednesday through 10 p.m. Thursday for most of northern and central Illinois, including all of Cook, DuPage, Lake, Kane, McHenry, Will, Kankakee, DeKalb, Grundy, La Salle, Kendall, Boone, Winnebago, Livingston, Iroquois, Lee, Ford, and Ogle Counties. Heat index values in the city of Chicago may stay above 90 degrees even overnight, putting residents at greater risk.
Communities across the region—Rockford, Aurora, Joliet, Kankakee, DeKalb, and Waukegan—should prepare for dangerous heat and humidity. The heat will be especially hazardous for those without air conditioning or access to cooling centers. City services are ramping up: Chicago residents can dial 311 for well-being checks or to find the nearest cooling center.
To stay safe: limit outdoor activity, drink water frequently, and check on elderly neighbors and vulnerable groups. Officials stress that heat-related illnesses—heat exhaustion and heat stroke—can develop rapidly in these conditions.
This stretch rivals some of the hottest July heat waves on record for Illinois. Extreme heat watches are rarely issued for such a wide area, underscoring the seriousness of this event. Updates or additional warnings are possible as conditions develop, so residents are urged to stay alert and monitor local advisories.
Warnings remain in effect through Thursday night. A slight cooldown is expected by early Friday, but further advisories may be issued if the heat persists.
