Indiana Weather in September

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

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

September is in the fall / autumn in Indiana 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.

Indiana weather averages (imperial / metric)
Daytime temperature 23.6°C 74.5°F
Nightly temperature 11°C 51.8°F
Average temperature 17.3°C 63.1°F
Daily sunshine 7 hrs
Avg rainfall 92 mm 3.6 ins
Rainy days 11 days
Sea temperature 21.1°C 70°F
Humidity 76%
Windspeed 12.2kph 8 mph

On average September is the 6th driest month of the year in Indiana with around 92mm 3.6 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 11 days, although this may vary considerably.

On the flip side this corresponds to an average of 7 hours of sunshine per day.

September temperatures in Indiana

Indiana average temperature in September

September rainfall

Indiana average rain in September

September hourly sunshine

Indiana 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 Indiana 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

Indiana weather stats

Indiana weather statistics
Hottest month: July 28.2°C 82.8°F
Driest month: October 75mm 3ins
Sunniest month: July 9.1hrs
Coldest month: January 0.9°C 33.6°F
Wettest month: July 121mm 4.8ins
Map showing location of Indiana (40.62146, -79.15253) Indiana map pin © Google

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