Gilroy Weather in September

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

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

September is in the fall / autumn in Gilroy and is typically the 3rd warmest month of the year. Daytime maximum temperatures average around a comfortable 27°C (80°F), whilst at night 11°C (51°F) is normal.

Gilroy weather averages (imperial / metric)
Daytime temperature 26.8°C 80.2°F
Nightly temperature 10.7°C 51.2°F
Average temperature 18.7°C 65.7°F
Daily sunshine 10.7 hrs
Avg rainfall 8 mm 0.3 ins
Rainy days 2 days
Sea temperature 14.9°C 58.9°F
Humidity 65%
Windspeed 14.4kph 9 mph

On average September is the 5th driest month of the year in Gilroy with around 8mm 0.3 inches of rain making it a very dry time to visit.

On the flip side this corresponds to an average of 10.7 hours of sunshine per day.

September temperatures in Gilroy

Gilroy average temperature in September

September rainfall

Gilroy average rain in September

September hourly sunshine

Gilroy 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 Gilroy 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

Gilroy weather stats

Gilroy weather statistics
Hottest month: August 27.3°C 81.1°F
Driest month: July 2mm 0.1ins
Sunniest month: April 11.3hrs
Coldest month: December 13.2°C 55.8°F
Wettest month: January 97mm 3.8ins
Map showing location of Gilroy (37.00578, -121.56828) Gilroy map pin © Google

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