Chicago, Ill. – Northern Illinois and northwest Indiana will see an active stretch of weather through Tuesday, with dangerous heat combining with multiple rounds of thunderstorms. Afternoon heat index values will reach 100 to 105°F each day, with some areas south of I-80 feeling closer to 110°F.
According to the National Weather Service Chicago, clusters of storms are likely tonight and Saturday, with the strongest activity expected Saturday afternoon and evening. These storms could bring torrential rainfall, damaging winds capable of downing trees, and frequent lightning. Flooding risk will be elevated in areas hit by repeated storms.
Chicago, Rockford, Joliet, and Gary may face travel delays from heavy rain and ponding on roads. Along the Lake Michigan shore, slightly cooler air will help offset peak heat, but inland communities should limit outdoor activities during the hottest hours. Residents are urged to stay hydrated, check on vulnerable neighbors, and ensure multiple ways to receive weather warnings.
Storm chances will taper slightly Sunday before increasing again Monday, with another round of hot, humid air and thunderstorms expected. Conditions should ease by midweek, though more alerts are possible if storm tracks shift.
Five Day Forecast for Chicago, Ill.
- Tonight: Lows 70–75°F, 40% chance of thunderstorms.
- Saturday: Highs 88–94°F, heat index up to 105°F, scattered storms, 30–40% chance.
- Sunday: Highs 86–94°F, 20–30% chance of storms, cooler near the lake.
- Monday: Highs 89–95°F, 40–50% chance of storms.
- Tuesday: Highs 84–91°F, 30% chance of storms.
