Weather For September 2024 Met Office Chicago. Sunrise is at 05:31 and sunset is at 17:59. Daily high temperatures decrease by 10°f, from 78°f to 68°f, rarely falling below 58°f or exceeding 86°f.

In september, chicago has a warm climate with an average temperature of 20.4°c (68.7°f). Get the monthly weather forecast for chicago, il, including daily high/low, historical averages, to help you plan ahead.