easeweather.com
Units
°C
°F
Winnebago County
Forecast Today Tomorrow
more
Illinois United States

Weather in Winnebago County for September 2025

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 28.6 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 23.9 °F by the end of September.

  • The climate of Winnebago County in September is notably wet, with an average of 13 rainy days.

  • New! Chat with our AI weatherman - it’s amazing and free.
Average dry days
17
Dry days
Average rainy days
13
Rainy days
Average snowy days
0
Snow days
Average temperatures
28°/12°
Temperatures
Average wind speed
19 km/h
Avg max wind
Average humidity
68 %
Avg humidity

Winnebago County in September average weather

Move between months or click on a day
Select a date

You can click on date

Access Winnebago County weather forecasts with a simple click. Select any date for comprehensive insights on temperature, rainfall, and wind conditions.
Got it

Temperatures trend during September in Winnebago County

See the weather trend as well as the moving average line

September weather day by day

Click on a date for more information
Date Weather Temperatures Rain UV More
Sept. 1 Sunny
Sunny
27° /10° 0 mm 7
Sept. 2 Mist
Mist
30° /11° 0 mm 7
Sept. 3 Partly cloudy
Partly cloudy
32° /12° 0 mm 8
Sept. 4 Cloudy
Cloudy
32° /14° 0 mm 7
Sept. 5 Overcast
Overcast
32° /18° 1.5 mm 7
Sept. 6 Patchy rain possible
Patchy rain possible
26° /13° 2 mm 6
Sept. 7 Patchy rain possible
Patchy rain possible
21° /7° 0.2 mm 6
Sept. 8 Mist
Mist
24° /7° 0 mm 6
Sept. 9 Mist
Mist
28° /8° 0 mm 7
Sept. 10 Fog
Fog
30° /10° 0 mm 7
Sept. 11 Light rain shower
Light rain shower
24° /13° 6.9 mm 6
Sept. 12 Fog
Fog
26° /12° 0 mm 6
Sept. 13 Mist
Mist
25° /12° 0 mm 6
Sept. 14 Mist
Mist
27° /10° 0.1 mm 6
Sept. 15 Mist
Mist
29° /12° 0 mm 7
Sept. 16 Light rain shower
Light rain shower
29° /15° 0.8 mm 7
Sept. 17 Light rain shower
Light rain shower
25° /11° 0.9 mm 6
Sept. 18 Mist
Mist
27° /8° 0 mm 6
Sept. 19 Moderate or heavy rain with thunder
Moderate or heavy rain with thunder
26° /11° 20.8 mm 6
Sept. 20 Patchy light drizzle
Patchy light drizzle
28° /15° 3.1 mm 6
Sept. 21 Patchy rain possible
Patchy rain possible
28° /14° 1.9 mm 7
Sept. 22 Cloudy
Cloudy
24° /14° 3.8 mm 6
Sept. 23 Mist
Mist
25° /9° 0 mm 6
Sept. 24 Patchy light drizzle
Patchy light drizzle
22° /11° 0.2 mm 5
Sept. 25 Fog
Fog
25° /13° 2.6 mm 6
Sept. 26 Moderate or heavy rain shower
Moderate or heavy rain shower
25° /11° 15.4 mm 6
Sept. 27 Light rain shower
Light rain shower
22° /11° 2.2 mm 5
Sept. 28 Patchy rain possible
Patchy rain possible
23° /13° 0 mm 5
Sept. 29 Mist
Mist
22° /12° 0 mm 5
Sept. 30 Thundery outbreaks possible
Thundery outbreaks possible
28° /15° 0 mm 6
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.

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 28° and cooler nights around 12°. 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 108.7 mm is expected in Winnebago County during September, occurring over more than 13 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 19 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 💧

UV exposure in Winnebago County during September

Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
Top locations in Winnebago County
Select a location for an accurate weather forecast
More Locations

Quick links

Location coordinates Where is Winnebago County?

Get accurate weather forecasts for Winnebago County, located at latitude 42.271 and longitude -89.094. Stay updated with localized weather information tailored for Winnebago County.

Found a mistake?
We appreciate your attention to details. Tell us here.