Weather Chicago September 2025

Weather Chicago September 2025. Get the monthly weather forecast for chicago, il, including daily high/low, historical averages, to help you plan ahead. Chicago —more than 100,000 people have already enjoyed the stunning holiday displays at millennium park, including the beloved chicago christmas tree, which sparkles.

Full weather forecast for chicago in september 2025. Weather.com brings you the most accurate monthly weather forecast for chicago, il, united states with average/record and high/low temperatures, precipitation and more.