Jefferson Weather in September

What's the weather like in Jefferson (Iowa) in September 2025?

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

September is in the fall / autumn in Jefferson and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 24°C (75°F), whilst at night 11°C (52°F) is normal.

Jefferson weather averages (imperial / metric)
Daytime temperature 24.1°C 75.3°F
Nightly temperature 11°C 51.7°F
Average temperature 17.5°C 63.5°F
Daily sunshine 8.6 hrs
Avg rainfall 94 mm 3.7 ins
Rainy days 9 days
Sea temperature 18.1°C 64.6°F
Humidity 72%
Windspeed 16.2kph 10 mph

On average September is the 5th wettest month of the year in Jefferson with around 94mm 3.7 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 8.6 hours of sunshine per day.

September temperatures in Jefferson

Jefferson average temperature in September

September rainfall

Jefferson average rain in September

September hourly sunshine

Jefferson 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 Jefferson 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

Jefferson weather stats

Jefferson weather statistics
Hottest month: July 29.8°C 85.6°F
Driest month: January 20mm 0.8ins
Sunniest month: July 11.6hrs
Coldest month: January -2.9°C 26.8°F
Wettest month: June 120mm 4.7ins
Map showing location of Jefferson (42.01526, -94.37747) Jefferson map pin © Google

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