New Castle Weather in September

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

The climate in New Castle during September can be summarized as mild and reasonably dry.

September is in the fall / autumn in New Castle and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 25°C (76°F), whilst at night 11°C (52°F) is normal.

New Castle weather averages (imperial / metric)
Daytime temperature 24.6°C 76.2°F
Nightly temperature 11.1°C 51.9°F
Average temperature 17.8°C 64°F
Daily sunshine 8.6 hrs
Avg rainfall 75 mm 3 ins
Rainy days 9 days
Sea temperature 21.9°C 71.4°F
Humidity 73%
Windspeed 13.3kph 8 mph

On average September is the 4th driest month of the year in New Castle with around 75mm 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 8.6 hours of sunshine per day.

September temperatures in New Castle

New Castle average temperature in September

September rainfall

New Castle average rain in September

September hourly sunshine

New Castle 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 New Castle 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

New Castle weather stats

New Castle weather statistics
Hottest month: July 28.4°C 83.1°F
Driest month: February 61mm 2.4ins
Sunniest month: July 10.5hrs
Coldest month: January -0°C 32°F
Wettest month: May 114mm 4.5ins
Map showing location of New Castle (39.92894, -85.37025) New Castle map pin © Google

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