Weather in DuPage County, Illinois for September 2026
Flood Watch - See hour by hour.
So far, September 2026 in DuPage County is slightly warmer than the historical average by 1.2 °F.
Expect cooler weather in the next days in DuPage County with the forecast suggesting a temperature of 17.4 °F, lower than the historical average.
In general, the average temperature in DuPage County at the beginning of September is 28 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 19.6 °F by the end of September.
The climate of DuPage County in September is notably wet, with an average of 11 rainy days, and a total of 102.7 mm of precipitation.
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DuPage County Weather September
Temperatures trend during September in DuPage County
September weather in DuPage County day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 29° /16° | 0.6 mm | 6 | |
| Sept. 2 | Sunny | 29° /17° | 0 mm | 7 | |
| Sept. 3 | Sunny | 31° /16° | 12.8 mm | 7 | |
| Sept. 4 |  Mist | 30° /16° | 0 mm | 7 | |
| Sept. 5 |  Overcast | 28° /17° | 0.6 mm | 7 | |
| Sept. 6 |  Patchy rain possible | 25° /14° | 2.4 mm | 6 | |
| Sept. 7 | Sunny | 24° /11° | 0 mm | 6 | |
| Sept. 8 | Overcast | 25° /11° | 0 mm | 5 | |
| Sept. 9 | Mist | 25° /13° | 9.8 mm | 5 | |
| Sept. 10 | Sunny | 28° /14° | 0 mm | 6 | |
| Sept. 11 | Sunny | 28° /15° | 10.6 mm | 7 | |
| Sept. 12 | Mist | 27° /14° | 0 mm | 6 | |
| Sept. 13 | Mist | 25° /15° | 0.4 mm | 5 | |
| Sept. 14 | Mist | 27° /15° | 0 mm | 7 | |
| Sept. 15 |  Cloudy | 29° /17° | 3 mm | 6 | |
| Sept. 16 | Sunny | 28° /16° | 1.2 mm | 6 | |
| Sept. 17 |  Light rain | 26° /16° | 4.9 mm | 5 | |
| Sept. 18 | Fog | 27° /14° | 0.9 mm | 5 | |
| Sept. 19 | Light rain shower | 26° /15° | 14.4 mm | 5 | |
| Sept. 20 | Light rain shower | 20° /15° | 91.5 mm | 0.5 | |
| Sept. 21 | Overcast | 16° /14° | 0 mm | 2.4 | |
| Sept. 22 | Patchy rain possible | 15° /12° | 0.8 mm | 1.7 | |
| Sept. 23 | Patchy rain possible | 16° /13° | 0.2 mm | 2.3 | |
| Sept. 24 | Overcast | 19° /13° | 0 mm | 5.3 | |
| Sept. 25 | Overcast | 19° /13° | 0 mm | 5 | |
| Sept. 26 | Overcast | 16° /14° | 0 mm | 4 | |
| Sept. 27 | Overcast | 20° /15° | 0 mm | 5 | |
| Sept. 28 | Sunny | 22° /13° | 0 mm | 6 | |
| Sept. 29 | Sunny | 21° /12° | 0 mm | 6 | |
| Sept. 30 | Light rain shower | 20° /12° | 3.4 mm | 4 | |
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DuPage County in September - FAQ
What are the expected maximum and minimum temperatures in DuPage County during September?
How much rainfall should be expected in DuPage County during September?
What are the typical wind conditions in DuPage County during September?
September rainfall patterns in DuPage County
UV exposure in DuPage County during September
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Where is DuPage County?Get accurate weather forecasts for DuPage County, located at latitude 41.786 and longitude -88.147. Stay updated with localized weather information tailored for DuPage County.