Chicago, Illinois – A surge of thunderstorms will roll through Illinois today, bringing the threat of torrential downpours and isolated severe weather, particularly south of I-80, before extreme heat settles in by midweek.
According to the National Weather Service in Chicago, a 70% chance of storms is expected through Saturday afternoon, with some producing high rainfall rates. The greatest flood and storm risk will be southwest of the metro area and near Lake Michigan, where rip currents and high swim risk are in effect.
Showers will persist into Sunday and Monday with off-and-on storms, especially south of I-80 and near Peoria and Kankakee. Highs will range from the upper 70s to low 80s, offering only temporary relief before dangerous heat arrives Tuesday. Wednesday and Thursday could see heat indices soar to 115°F across the Chicago metro, Rockford, and much of northern Illinois.
Residents should limit outdoor activity during peak heat hours, hydrate frequently, and check on vulnerable neighbors. Power grid strain and heat-related illness will be key concerns.
Excessive Heat Watches are likely to be issued Monday. Updates are expected daily through the upcoming heat wave.
🔎 Five-Day Illinois Forecast
- Saturday: Thunderstorms likely (70%), humid; High 82–86°F / Low 65–70°F
- Sunday: Scattered storms, high swim risk; High 74–82°F / Low 60–70°F
- Monday: Spotty storms; High 78–83°F / Low 64–70°F
- Tuesday: Mostly sunny, hotter, humid; High 84–89°F / Low 70–75°F
- Wednesday: Dangerously Hot; High 92–95°F (Heat Index 105–115°) / Low 72–77°F
- Thursday: Continued extreme heat; High 90–94°F / Low 69–73°F
