Chicago, Illinois –Extreme heat and oppressive humidity will blanket much of Illinois starting Sunday and peak Monday, with heat indices soaring to 110°F in some areas and a rising risk of storms into midweek.
According to the National Weather Service in Chicago, dangerously high heat indices between 105°F and 110°F are expected Monday, especially inland from Lake Michigan. A Heat Advisory may be issued if these conditions persist. Humid air and heat continue through Tuesday, with the potential for scattered storms increasing late Tuesday and into Wednesday.
Cities south of I-80 may see lingering thunderstorms tonight. By Monday, areas like Joliet, Aurora, and Kankakee could feel the brunt of the heat. Commuters and outdoor workers should stay hydrated, limit exertion, and take frequent breaks in the shade or air conditioning.
Wednesday brings the highest chance of widespread thunderstorms across northern Illinois, potentially disrupting commutes and posing risks for swimmers due to strong currents and lightning threats along Lake Michigan.
Residents should stay alert for evolving alerts, especially as humidity fuels midweek storm development.
⚠️ Next update expected Monday morning. Warnings may be issued as heat and storms intensify.
📅 Illinois 5-Day Weather Outlook
- Sunday: Humid, Highs 87–91°F, Lows 72–76°F. Peak heat index 105° inland.
- Monday: Very humid, Highs 91–95°F, Lows 72–77°F. Heat index 105°–110°.
- Tuesday: Storm chance 20%, Highs 88–92°F, Lows 66–72°F.
- Wednesday: Thunderstorms likely, Highs 77–86°F, Lows 60–68°F. Swimming danger.
- Thursday: Cooler and less humid, Highs in upper 70s, continued storm potential early.
