Chicago Weather September 2025

Chicago Weather September 2025. Explore comprehensive september 2025 weather forecasts for chicago, including daily high and low temperatures, precipitation risks, and monthly temperature trends. See the long range weather forecast for chicago, check the 30 days forecast view, select a month and get the average expected weather for chicago.

Discover the most accurate weather forecast for illinois in september 2025. Expect chicago september temperature around 24°c (75°f).