San Jose Weather in September

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

The climate in San Jose during September can be summarized as warm and very dry.

September is in the fall / autumn in San Jose and is typically the 3rd warmest month of the year. Daytime maximum temperatures average around a comfortable 27°C (81°F), whilst at night 12°C (54°F) is normal.

San Jose weather averages (imperial / metric)
Daytime temperature 27.1°C 80.7°F
Nightly temperature 12.2°C 53.9°F
Average temperature 19.6°C 67.3°F
Daily sunshine 10.5 hrs
Avg rainfall 6 mm 0.2 ins
Rainy days 1 days
Sea temperature 14.9°C 58.9°F
Humidity 66%
Windspeed 15.5kph 10 mph

On average September is the 4th driest month of the year in San Jose with around 6mm 0.2 inches of rain making it a very dry time to visit.

On the flip side this corresponds to an average of 10.5 hours of sunshine per day.

September temperatures in San Jose

San Jose average temperature in September

September rainfall

San Jose average rain in September

September hourly sunshine

San Jose 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 San Jose 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

San Jose weather stats

San Jose weather statistics
Hottest month: August 27.5°C 81.5°F
Driest month: July 1mm 0ins
Sunniest month: April 11.3hrs
Coldest month: December 13.8°C 56.8°F
Wettest month: January 81mm 3.2ins
Map showing location of San Jose (37.33939, -121.89496) San Jose map pin © Google

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