Forecast: Heat and humidity return as storms move out

After back-to-back days of drenching rain that caused flooding in some Chicago neighborhoods, a break from the rain is coming.

Sunday is expected to bring drier skies, but the heat and humidity will ramp up. Temperatures will climb to around 90 degrees, though it will be cooler near the lakefront.

Skies will be partly cloudy and while most of the day should stay dry, a stray storm can’t be ruled out.

Heat expands across the Lower 48 with 174 million U.S. residents reaching at least 90 degrees on Sunday, but that number increases to 261 million by Monday, the hottest day across the U.S. of 2025 so far. The lower 48 forecast average temperature on Monday is predicted to be 90.5 degrees.

Chicago forecast highs and departure from normal

The heat peaks on Monday with a noticeable cool-down expected by mid to late next week when a stretch of below normal temperatures is likely. 

A significant pattern change sends the heat and humidity packing to the deep south while cooler than normal temperatures dominate the Midwest, Great Lakes and Northeast.