Chicago, Illinois – Drivers and residents in Cook County will face a final blast of summer heat today as highs climb into the mid-80s before a cooler fall pattern sets in by Monday. Temperatures could reach 86 degrees in the city this afternoon, keeping pavement hot along I-90 and Lake Shore Drive and adding stress for outdoor workers and travelers.
According to the National Weather Service, sunshine dominates through Sunday with lighter winds, but a drop into the low-to-mid 70s begins Monday, September 29. Humidity remains moderate, and while the weekend stays dry, breezes may pick up near the lakefront late Sunday. By early next week, cooler air settles in across northern Illinois, signaling a clear shift toward October conditions.
The warm stretch benefits weekend outdoor plans across downtown Chicago, Navy Pier, and Wrigleyville, but city officials urge residents to stay hydrated and limit prolonged sun exposure during peak afternoon hours. Evening lows dip to the mid-60s, offering some relief before the transition arrives.
By midweek, highs near 72 are expected, aligning with fall norms across the region. Commuters should prepare for brisker mornings starting Tuesday, with jackets needed at bus stops and train platforms. The change offers a reminder that October begins Wednesday, and more noticeable autumn air will likely follow.
Five Day Forecast for Chicago, Illinois:
- Saturday: Sunny, high near 86.
- Sunday: Sunny, high near 74.
- Monday: Sunny, high near 78.
- Tuesday: Sunny, high near 76.
- Wednesday: Mostly sunny, high near 73.
