Winnebago County (Rockford)
September
Weather in Winnebago County, Illinois for September 2027
Your guide to Winnebago County weather in September - trends and predictions
In general, the average temperature in Winnebago County at the beginning of September is 27.9 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 23.3 °C by the end of September.
Winnebago County experiences moderate rainfall in September, with an average of 8 rainy days and a total precipitation of 121.6 mm.
Is September a good time to visit Winnebago County? check out the best time to travel to Winnebago County page.
✨ Is September a good time to visit Winnebago County? – Ask the AI Weatherman
Temperatures
Rain 🌧️
More
22
Dry days
8
Rainy days
0
Snow days
26°/13°
Temperatures
18 km/h
Avg max wind
72 %
Avg humidity
Winnebago County Weather September
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Temperatures trend during September in Winnebago County
See the weather trend as well as the moving average line
September weather in Winnebago County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 29° /13° | 0 mm | 7 | |
| Sept. 2 | Sunny | 30° /13° | 0 mm | 7 | |
| Sept. 3 |  Light rain | 30° /15° | 8.6 mm | 7 | |
| Sept. 4 |  Cloudy | 30° /15° | 0 mm | 6 | |
| Sept. 5 |  Overcast | 29° /17° | 0.8 mm | 6 | |
| Sept. 6 |  Patchy rain possible | 25° /11° | 1 mm | 5 | |
| Sept. 7 | Patchy rain possible | 23° /8° | 0.1 mm | 5 | |
| Sept. 8 |  Mist | 24° /9° | 0 mm | 5 | |
| Sept. 9 |  Moderate rain | 27° /11° | 16.9 mm | 5 | |
| Sept. 10 | Fog | 28° /12° | 0 mm | 6 | |
| Sept. 11 | Light rain | 26° /13° | 3.5 mm | 6 | |
| Sept. 12 | Fog | 27° /13° | 0 mm | 6 | |
| Sept. 13 | Mist | 25° /14° | 0.6 mm | 6 | |
| Sept. 14 | Mist | 27° /11° | 0 mm | 6 | |
| Sept. 15 | Light rain | 29° /15° | 5.8 mm | 6 | |
| Sept. 16 | Light rain shower | 28° /15° | 1.3 mm | 5 | |
| Sept. 17 | Light rain | 26° /12° | 9.8 mm | 5 | |
| Sept. 18 | Mist | 26° /12° | 0.6 mm | 6 | |
| Sept. 19 |  Moderate or heavy rain with thunder | 26° /14° | 26.5 mm | 5 | |
| Sept. 20 | Moderate rain | 24° /16° | 19.7 mm | 5 | |
| Sept. 21 | Light rain | 23° /15° | 2.5 mm | 5 | |
| Sept. 22 | Light rain | 22° /14° | 8.8 mm | 5 | |
| Sept. 23 | Mist | 23° /11° | 0 mm | 5 | |
| Sept. 24 | Overcast | 21° /12° | 0.1 mm | 5 | |
| Sept. 25 | Patchy rain possible | 22° /12° | 1.6 mm | 4 | |
| Sept. 26 | Light rain | 24° /11° | 7.7 mm | 5 | |
| Sept. 27 | Light rain shower | 23° /11° | 1.1 mm | 5 | |
| Sept. 28 | Patchy rain possible | 23° /13° | 0 mm | 5 | |
| Sept. 29 | Mist | 24° /12° | 0 mm | 5 | |
| Sept. 30 | Light rain | 26° /15° | 4.5 mm | 5 | |
| Next | |||||
Important Notice
Our weather forecast for Winnebago 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 Winnebago County forecast closer to your planned date for the most up-to-date weather information.
Change Month
Winnebago County in September - FAQ
What are the expected maximum and minimum temperatures in Winnebago County during September?
Enjoy moderate daytime temperatures of up to 26° and cooler nights around 13°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Winnebago County during September?
Significant rainfall exceeding 121.6 mm is expected in Winnebago County during September, occurring over more than 8 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Winnebago County during September?
The average wind speed in Winnebago County during September is 18 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Winnebago County
Explore the daily rainfall trends and prepare for Winnebago Countys September weather 💧
Typically, Winnebago County has 8 rainy days in September with a total of 121.6 mm of rainfall.
UV exposure in Winnebago County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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