Belvidere Weather in September

What's the weather like in Belvidere (Illinois) in September 2025?

The climate in Belvidere during September can be summarized as mild and a little damp.

September is in the fall / autumn in Belvidere and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 23°C (74°F), whilst at night 10°C (51°F) is normal.

Belvidere weather averages (imperial / metric)
Daytime temperature 23.4°C 74.1°F
Nightly temperature 10.4°C 50.7°F
Average temperature 16.9°C 62.4°F
Daily sunshine 8 hrs
Avg rainfall 97 mm 3.8 ins
Rainy days 9 days
Sea temperature 19.2°C 66.5°F
Humidity 74%
Windspeed 14.8kph 9 mph

On average September is the 4th wettest month of the year in Belvidere with around 97mm 3.8 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 9 days, although this may vary considerably.

On the flip side this corresponds to an average of 8 hours of sunshine per day.

September temperatures in Belvidere

Belvidere average temperature in September

September rainfall

Belvidere average rain in September

September hourly sunshine

Belvidere average rain in September

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Belvidere in September 2025.

Other monthly averages

Best places to visit in September

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

Belvidere weather stats

Belvidere weather statistics
Hottest month: July 28.7°C 83.7°F
Driest month: February 28mm 1.1ins
Sunniest month: July 10.8hrs
Coldest month: January -3.2°C 26.2°F
Wettest month: June 111mm 4.4ins
Map showing location of Belvidere (42.26391, -88.84427) Belvidere map pin © Google

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