Will County (Joliet)
September
Weather in Will County, Illinois for September 2027
Your guide to Will County weather in September - trends and predictions
In general, the average temperature in Will County at the beginning of September is 28.4 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 23.7 °C by the end of September.
Will County experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 138 mm.
Is September a good time to visit Will County? check out the best time to travel to Will County page.
✨ Is September a good time to visit Will County? – Ask the AI Weatherman
Temperatures
Rain 🌧️
More
23
Dry days
7
Rainy days
0
Snow days
26°/14°
Temperatures
17 km/h
Avg max wind
70 %
Avg humidity
Will County Weather September
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Temperatures trend during September in Will County
See the weather trend as well as the moving average line
September weather in Will County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Light rain | 29° /15° | 3.9 mm | 6 | |
| Sept. 2 |  Sunny | 30° /16° | 0 mm | 7 | |
| Sept. 3 | Light rain | 31° /16° | 7.5 mm | 7 | |
| Sept. 4 |  Mist | 31° /15° | 0 mm | 7 | |
| Sept. 5 | Sunny | 29° /17° | 0.9 mm | 7 | |
| Sept. 6 |  Patchy rain possible | 25° /13° | 1.3 mm | 6 | |
| Sept. 7 | Sunny | 24° /11° | 0 mm | 6 | |
| Sept. 8 |  Partly cloudy | 25° /10° | 0 mm | 6 | |
| Sept. 9 |  Heavy rain | 26° /13° | 34.4 mm | 5 | |
| Sept. 10 | Partly cloudy | 28° /13° | 0.4 mm | 6 | |
| Sept. 11 | Light rain | 28° /15° | 8.3 mm | 7 | |
| Sept. 12 | Fog | 28° /14° | 0 mm | 7 | |
| Sept. 13 | Mist | 26° /15° | 0 mm | 6 | |
| Sept. 14 | Mist | 27° /14° | 0 mm | 6.8 | |
| Sept. 15 | Patchy rain possible | 29° /17° | 2.2 mm | 6 | |
| Sept. 16 | Patchy rain possible | 28° /15° | 2.3 mm | 6 | |
| Sept. 17 | Light rain | 26° /15° | 5 mm | 5 | |
| Sept. 18 | Mist | 27° /13° | 0.8 mm | 6 | |
| Sept. 19 |  Moderate rain | 26° /15° | 9.2 mm | 5 | |
| Sept. 20 | Moderate rain | 26° /16° | 17 mm | 5 | |
| Sept. 21 | Patchy rain possible | 24° /15° | 1.5 mm | 5 | |
| Sept. 22 | Light rain | 22° /14° | 9.5 mm | 4 | |
| Sept. 23 | Moderate rain | 24° /14° | 14.3 mm | 5 | |
| Sept. 24 |  Overcast | 22° /13° | 0.2 mm | 5 | |
| Sept. 25 | Fog | 23° /15° | 0.1 mm | 5 | |
| Sept. 26 | Light rain | 24° /12° | 7.1 mm | 5 | |
| Sept. 27 | Light rain | 24° /13° | 2.5 mm | 5 | |
| Sept. 28 | Overcast | 23° /14° | 0 mm | 5 | |
| Sept. 29 | Fog | 25° /14° | 0 mm | 5.4 | |
| Sept. 30 | Light rain | 25° /15° | 9.4 mm | 5 | |
| Next | |||||
Important Notice
Our weather forecast for Will County 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 Will County forecast closer to your planned date for the most up-to-date weather information.
Change Month
Will County in September - FAQ
What are the expected maximum and minimum temperatures in Will County during September?
Enjoy moderate daytime temperatures of up to 26° and cooler nights around 14°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Will County during September?
Significant rainfall exceeding 138 mm is expected in Will County during September, occurring over more than 7 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Will County during September?
The average wind speed in Will County during September is 17 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Will County
Explore the daily rainfall trends and prepare for Will Countys September weather 💧
Typically, Will County has 7 rainy days in September with a total of 138 mm of rainfall.
UV exposure in Will County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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