Jamestown Weather in September

What's the weather like in Jamestown (California) in September 2025?

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

September is in the fall / autumn in Jamestown and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a comfortable 30°C (87°F), whilst at night 11°C (52°F) is normal.

Jamestown weather averages (imperial / metric)
Daytime temperature 30.4°C 86.6°F
Nightly temperature 11.1°C 51.9°F
Average temperature 20.7°C 69.3°F
Daily sunshine 12.2 hrs
Avg rainfall 13 mm 0.5 ins
Rainy days 2 days
Sea temperature 16°C 60.7°F
Humidity 50%
Windspeed 11.9kph 7 mph

On average September is the 4th driest month of the year in Jamestown with around 13mm 0.5 inches of rain making it a dry time to visit. This rainfall is typically spread over 2 days, although this may vary considerably.

On the flip side this corresponds to an average of 12.2 hours of sunshine per day.

September temperatures in Jamestown

Jamestown average temperature in September

September rainfall

Jamestown average rain in September

September hourly sunshine

Jamestown 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 Jamestown 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

Jamestown weather stats

Jamestown weather statistics
Hottest month: July 34.1°C 93.4°F
Driest month: July 2mm 0.1ins
Sunniest month: July 14.6hrs
Coldest month: December 11.2°C 52.2°F
Wettest month: January 132mm 5.2ins
Map showing location of Jamestown (37.95326, -120.4227) Jamestown map pin © Google

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