Champaign (IL)
September
Weather in Champaign, Illinois for September 2026
Your guide to Champaign weather in September - trends and predictions
So far, September 2026 in Champaign is slightly warmer than the historical average by 1.9 °F.
Expect cooler weather in the next days in Champaign with the forecast suggesting a temperature of 19.9 °F, lower than the historical average.
In general, the average temperature in Champaign at the beginning of September is 29.3 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 20.9 °F by the end of September.
Champaign experiences moderate rainfall in September, with an average of 8 rainy days and a total precipitation of 96.5 mm.
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Temperatures
Rain 🌧️
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22
Dry days
8
Rainy days
0
Snow days
27°/14°
Temperatures
16 km/h
Avg max wind
69 %
Avg humidity
Champaign Weather September
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Temperatures trend during September in Champaign
See the weather trend as well as the moving average line
September weather in Champaign day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Partly cloudy | 33° /15° | 0 mm | 8 | |
| Sept. 2 | Partly cloudy | 32° /16° | 0 mm | 8 | |
| Sept. 3 |  Fog | 31° /18° | 1.6 mm | 7 | |
| Sept. 4 | Mist | 29° /17° | 0.8 mm | 7 | |
| Sept. 5 |  Overcast | 28° /16° | 0 mm | 7 | |
| Sept. 6 | Mist | 26° /13° | 0 mm | 7 | |
| Sept. 7 |  Sunny | 26° /11° | 0 mm | 7 | |
| Sept. 8 | Sunny | 28° /10° | 0 mm | 7 | |
| Sept. 9 | Overcast | 26° /14° | 5.1 mm | 5 | |
| Sept. 10 |  Cloudy | 26° /15° | 8.1 mm | 4 | |
| Sept. 11 | Overcast | 28° /15° | 0 mm | 4 | |
| Sept. 12 | Overcast | 31° /16° | 0.2 mm | 7 | |
| Sept. 13 |  Thundery outbreaks possible | 26° /17° | 0 mm | 7 | |
| Sept. 14 | Thundery outbreaks possible | 30° /16° | 0 mm | 8 | |
| Sept. 15 | Mist | 33° /20° | 0.8 mm | 6 | |
| Sept. 16 | Sunny | 31° /17° | 4.8 mm | 5 | |
| Sept. 17 | Overcast | 31° /18° | 1.2 mm | 6 | |
| Sept. 18 | Overcast | 28° /17° | 8.9 mm | 5 | |
| Sept. 19 | Thundery outbreaks possible | 30° /17° | 5.5 mm | 5 | |
| Sept. 20 |  Light rain shower | 27° /17° | 8.4 mm | 5.1 | |
| Sept. 21 | Patchy rain possible | 18° /14° | 2.6 mm | 2.1 | |
| Sept. 22 | Overcast | 19° /13° | 0 mm | 4.3 | |
| Sept. 23 | Overcast | 19° /13° | 0.2 mm | 5.4 | |
| Sept. 24 | Overcast | 19° /13° | 0 mm | 3.9 | |
| Sept. 25 | Overcast | 20° /12° | 0 mm | 5 | |
| Sept. 26 | Overcast | 16° /13° | 0 mm | 4 | |
| Sept. 27 | Partly cloudy | 21° /13° | 0 mm | 6 | |
| Sept. 28 | Sunny | 23° /13° | 0 mm | 6 | |
| Sept. 29 | Sunny | 26° /12° | 0 mm | 7 | |
| Sept. 30 | Overcast | 21° /15° | 3 mm | 6 | |
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Important Notice
Our weather forecast for Champaign 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 Champaign forecast closer to your planned date for the most up-to-date weather information.
Change Month
Champaign in September - FAQ
What are the expected maximum and minimum temperatures in Champaign during September?
Enjoy moderate daytime temperatures of up to 27° and cooler nights around 14°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Champaign during September?
Moderate rainfall is anticipated in Champaign during September, with a total of 96.5 mm spread over approximately 8 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Champaign during September?
The average wind speed in Champaign during September is 16 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Champaign
Explore the daily rainfall trends and prepare for Champaigns September weather 💧
Typically, Champaign has 8 rainy days in September with a total of 96.5 mm of rainfall.
UV exposure in Champaign during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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