Decatur Weather in September

What's the weather like in Decatur (Indiana) in September 2025?

The climate in Decatur during September can be summarized as warm and reasonably dry.

September is in the fall / autumn in Decatur and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 25°C (77°F), whilst at night 12°C (54°F) is normal.

Decatur weather averages (imperial / metric)
Daytime temperature 24.7°C 76.5°F
Nightly temperature 12.1°C 53.8°F
Average temperature 18.4°C 65.1°F
Daily sunshine 8.9 hrs
Avg rainfall 77 mm 3 ins
Rainy days 9 days
Sea temperature 21.3°C 70.4°F
Humidity 73%
Windspeed 13.7kph 9 mph

On average September is the 6th driest month of the year in Decatur with around 77mm 3 inches of rain making it a reasonably dry 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 8.9 hours of sunshine per day.

September temperatures in Decatur

Decatur average temperature in September

September rainfall

Decatur average rain in September

September hourly sunshine

Decatur 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 Decatur 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

Decatur weather stats

Decatur weather statistics
Hottest month: July 29.2°C 84.6°F
Driest month: February 53mm 2.1ins
Sunniest month: July 11.4hrs
Coldest month: January -0.4°C 31.3°F
Wettest month: June 105mm 4.1ins
Map showing location of Decatur (40.8306, -84.92913) Decatur map pin © Google

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