Ottumwa Weather in September

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

The climate in Ottumwa during September can be summarized as warm and a little damp.

September is in the fall / autumn in Ottumwa and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 25°C (76°F), whilst at night 13°C (55°F) is normal.

Ottumwa weather averages (imperial / metric)
Daytime temperature 24.5°C 76.1°F
Nightly temperature 12.7°C 54.9°F
Average temperature 18.6°C 65.5°F
Daily sunshine 8.4 hrs
Avg rainfall 98 mm 3.9 ins
Rainy days 9 days
Sea temperature 18.9°C 66.1°F
Humidity 72%
Windspeed 15.5kph 10 mph

On average September is the 5th wettest month of the year in Ottumwa with around 98mm 3.9 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 8.4 hours of sunshine per day.

September temperatures in Ottumwa

Ottumwa average temperature in September

September rainfall

Ottumwa average rain in September

September hourly sunshine

Ottumwa 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 Ottumwa 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

Ottumwa weather stats

Ottumwa weather statistics
Hottest month: July 30°C 86°F
Driest month: February 25mm 1ins
Sunniest month: July 11.1hrs
Coldest month: January -1.5°C 29.3°F
Wettest month: July 112mm 4.4ins
Map showing location of Ottumwa (41.02001, -92.4113) Ottumwa map pin © Google

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