Chicago (IL)
September
Weather in Chicago, Illinois for September 2026
Your guide to Chicago weather in September - trends and predictions
So far, September 2026 in Chicago is slightly warmer than the historical average by 1.1 °F.
The forecast for the next days in Chicago predicts temperatures to be around 25 °F, close to the historical average.
In general, the average temperature in Chicago at the beginning of September is 25.6 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 21.9 °F by the end of September.
Chicago experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 74.3 mm.
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Temperatures
Rain 🌧️
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23
Dry days
7
Rainy days
0
Snow days
24°/17°
Temperatures
19 km/h
Avg max wind
66 %
Avg humidity
Chicago Weather September
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Temperatures trend during September in Chicago
See the weather trend as well as the moving average line
September weather in Chicago day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 26° /18° | 0.1 mm | 6 | |
| Sept. 2 |  Partly cloudy | 27° /19° | 0 mm | 7 | |
| Sept. 3 | Sunny | 27° /17° | 7 mm | 6 | |
| Sept. 4 |  Moderate rain at times | 26° /18° | 0.4 mm | 6 | |
| Sept. 5 | Sunny | 26° /18° | 0.2 mm | 6 | |
| Sept. 6 | Sunny | 24° /18° | 1.9 mm | 6 | |
| Sept. 7 |  Patchy rain possible | 23° /16° | 2.5 mm | 6 | |
| Sept. 8 | Sunny | 24° /16° | 0 mm | 6 | |
| Sept. 9 | Sunny | 25° /17° | 4.4 mm | 5 | |
| Sept. 10 | Sunny | 26° /17° | 0 mm | 6 | |
| Sept. 11 | Sunny | 28° /18° | 0 mm | 6.6 | |
| Sept. 12 | Sunny | 29° /20° | 0 mm | 6.6 | |
| Sept. 13 |  Overcast | 25° /19° | 3.3 mm | 6.1 | |
| Sept. 14 | Sunny | 30° /19° | 2.2 mm | 2.1 | |
| Sept. 15 | Patchy rain possible | 31° /22° | 1.2 mm | 7 | |
| Sept. 16 | Patchy rain possible | 22° /16° | 8.1 mm | 4 | |
| Sept. 17 | Overcast | 21° /16° | 0 mm | 6 | |
| Sept. 18 | Sunny | 25° /15° | 0 mm | 6 | |
| Sept. 19 | Sunny | 27° /16° | 0 mm | 7 | |
| Sept. 20 | Overcast | 25° /18° | 0 mm | 7 | |
| Sept. 21 | Light rain shower | 22° /16° | 3.8 mm | 5 | |
| Sept. 22 |  Cloudy | 25° /16° | 0 mm | 6 | |
| Sept. 23 | Overcast | 18° /12° | 0 mm | 4 | |
| Sept. 24 | Overcast | 22° /15° | 2.1 mm | 5 | |
| Sept. 25 | Overcast | 22° /15° | 0.6 mm | 5 | |
| Sept. 26 |  Mist | 23° /14° | 5.1 mm | 6 | |
| Sept. 27 | Sunny | 23° /15° | 1.9 mm | 5 | |
| Sept. 28 | Patchy rain possible | 19° /15° | 0.1 mm | 5 | |
| Sept. 29 | Sunny | 22° /15° | 2.1 mm | 5 | |
| Sept. 30 | Sunny | 22° /16° | 0 mm | 6 | |
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Important Notice
Our weather forecast for Chicago in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Chicago forecast closer to your planned date for the most up-to-date weather information.
Change Month
Chicago in September - FAQ
What are the expected maximum and minimum temperatures in Chicago during September?
During September, expect a variety of temperatures with highs around 24° and lows near 17°, suitable for diverse activities and preferences.
How much rainfall should be expected in Chicago during September?
Moderate rainfall is anticipated in Chicago during September, with a total of 74.3 mm spread over approximately 7 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Chicago during September?
The average wind speed in Chicago during September is 19 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Chicago
Explore the daily rainfall trends and prepare for Chicagos September weather 💧
Typically, Chicago has 7 rainy days in September with a total of 74.3 mm of rainfall.
UV exposure in Chicago during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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