Redwood City Weather in September

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

The climate in Redwood City during September can be summarized as mild and very dry.

September is in the fall / autumn in Redwood City and is typically the 2nd warmest month of the year. Daytime maximum temperatures average around a comfortable 24°C (75°F), whilst at night 12°C (53°F) is normal.

Redwood City weather averages (imperial / metric)
Daytime temperature 23.8°C 74.8°F
Nightly temperature 11.9°C 53.3°F
Average temperature 17.8°C 64°F
Daily sunshine 10 hrs
Avg rainfall 7 mm 0.3 ins
Rainy days 2 days
Sea temperature 14.4°C 57.9°F
Humidity 70%
Windspeed 16.2kph 10 mph

On average September is the 4th driest month of the year in Redwood City with around 7mm 0.3 inches of rain making it a very dry time to visit.

On the flip side this corresponds to an average of 10 hours of sunshine per day.

September temperatures in Redwood City

Redwood City average temperature in September

September rainfall

Redwood City average rain in September

September hourly sunshine

Redwood City 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 Redwood City 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

Redwood City weather stats

Redwood City weather statistics
Hottest month: August 23.3°C 73.9°F
Driest month: July 2mm 0.1ins
Sunniest month: April 11.1hrs
Coldest month: January 13.3°C 55.9°F
Wettest month: January 133mm 5.2ins
Map showing location of Redwood City (37.48522, -122.23635) Redwood City map pin © Google

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