New Castle Weather in September

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

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

September is in the fall / autumn in New Castle and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 24°C (75°F), whilst at night 10°C (50°F) is normal.

New Castle weather averages (imperial / metric)
Daytime temperature 23.6°C 74.5°F
Nightly temperature 10.2°C 50.4°F
Average temperature 16.9°C 62.4°F
Daily sunshine 7 hrs
Avg rainfall 87 mm 3.4 ins
Rainy days 11 days
Sea temperature 20.6°C 69.2°F
Humidity 75%
Windspeed 13.7kph 9 mph

On average September is the 4th wettest month of the year in New Castle with around 87mm 3.4 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 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 27.8°C 82°F
Driest month: February 56mm 2.2ins
Sunniest month: July 9.2hrs
Coldest month: January 0.1°C 32.2°F
Wettest month: July 103mm 4.1ins
Map showing location of New Castle (41.00367, -80.34701) New Castle map pin © Google

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