Grantsville Weather in September

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

September is in the fall / autumn in Grantsville and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a comfortable 26°C (78°F), whilst at night 11°C (51°F) is normal.

On average September is the 5th driest month of the year in Grantsville with around 24mm 0.9 inches of rain making it a dry time to visit. This rainfall is typically spread over 6 days, although this may vary considerably.

On the flip side this corresponds to an average of 10.8 hours of sunshine per day.

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 Grantsville in September 2025.