Chicago, Illinois – Dangerous heat and humidity are gripping northern Illinois today, with peak heat indices approaching 100 degrees across much of the region, sparking concerns for isolated strong thunderstorms late this afternoon.
According to the National Weather Service in Chicago, highs will climb into the mid-90s away from the immediate lakeshore, where slightly cooler air is expected. Storm chances remain limited—only about 20 to 30 percent—but any developing cells could produce isolated downburst winds and heavy rainfall, especially near Lake Michigan.
The hot and unstable conditions could spark storms mainly between 2 p.m. and 8 p.m., with areas south of I-80 and along I-55 seeing the greatest risk. Monday brings a higher potential for strong to severe storms, especially in the late afternoon and evening hours as a cold front approaches. Early Monday storms may also track across parts of east-central Illinois.
Residents are urged to avoid outdoor activity during peak heat and have multiple ways to receive weather alerts. Cooling centers may be needed if power outages occur during storms.
Storm chances taper Tuesday, bringing cooler, drier air before summer heat returns midweek.
More advisories are possible Monday depending on storm strength and timing.
🔎 Five Day Forecast for Northern Illinois
- Sunday: High 90–95°F | Isolated PM storms | Heat index near 100° | Low 70–75°F
- Monday: High 82–87°F | Scattered storms, some strong | Low 63–70°F
- Tuesday: High 77–85°F | Drier, less humid | Low 62–70°F
- Wednesday: High 85–88°F | Mostly sunny | Low 66–72°F
- Thursday: High near 90°F | Hot, humid return | Storms possible PM
