Newcastle Weather in September

What's the weather like in Newcastle (Wyoming) in September 2025?

The climate in Newcastle during September can be summarized as mild and dry.

September is in the fall / autumn in Newcastle and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 22°C (72°F), whilst at night 7°C (45°F) is normal.

Newcastle weather averages (imperial / metric)
Daytime temperature 22.2°C 71.9°F
Nightly temperature 7.1°C 44.7°F
Average temperature 14.6°C 58.3°F
Daily sunshine 9.3 hrs
Avg rainfall 29 mm 1.1 ins
Rainy days 8 days
Sea temperature 16.1°C 61°F
Humidity 54%
Windspeed 17.3kph 11 mph

On average September is the 6th wettest month of the year in Newcastle with around 29mm 1.1 inches of rain making it a dry time to visit. This rainfall is typically spread over 8 days, although this may vary considerably.

On the flip side this corresponds to an average of 9.3 hours of sunshine per day.

September temperatures in Newcastle

Newcastle average temperature in September

September rainfall

Newcastle average rain in September

September hourly sunshine

Newcastle 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 Newcastle 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

Newcastle weather stats

Newcastle weather statistics
Hottest month: July 29.2°C 84.6°F
Driest month: January 11mm 0.4ins
Sunniest month: August 11hrs
Coldest month: January -0.3°C 31.5°F
Wettest month: June 67mm 2.6ins
Map showing location of Newcastle (43.8547, -104.20494) Newcastle map pin © Google

Locations nearby

Top United States locations