Chicago, Illinois – Hot and humid air will blanket northern Illinois on Sunday, bringing heat index values near 100°F and sparking afternoon thunderstorms—especially northeast of I-90.
According to the National Weather Service in Chicago, isolated to scattered storms may develop after 4 p.m. Sunday, with the highest storm chances in Lake, McHenry, and Cook counties. Stronger storms capable of gusty winds are possible into Sunday night, with additional activity expected along the I-80 corridor through Monday.
Chicago could see highs near 94°F Sunday, with nighttime temperatures staying in the mid-70s. Areas like Joliet, Kankakee, and Waukegan should be prepared for sudden downpours and brief power outages. Travel on interstates I-57 and I-80 may be impacted by heavy rain and reduced visibility Monday morning.
Residents are advised to limit outdoor activity during peak heat, stay hydrated, and monitor local alerts. Use air conditioning or visit cooling centers if needed.
Less humid air returns Tuesday, with highs in the upper 70s and a dry pattern continuing through midweek.
