San Francisco Weather in September

What's the weather like in San Francisco, United States in September 2018?

The climate in San Francisco during September can be summarized as mild and very dry.

September is in the fall / autumn in San Francisco and is typically the warmest month of the year. Daytime maximum temperatures average around 22°C (71°F), whilst at night 13°C (55°F) is normal.

San Francisco weather averages (imperial / metric)
Daytime temperature 21.6°C 70.9°F
Nightly temperature 13°C 55.4°F
Average temperature 17.3°C 63.1°F
Daily sunshine 9.9 hrs
Avg rainfall 7 mm 0.3 ins
Rainy days 2 days
Sea temperature 14.4°C 57.9°F
Humidity 70%
Windspeed 16.6kph 10 mph

On average September is the 4th driest month of the year in San Francisco 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 9.9 hours of sunshine per day.

September temperatures in San Francisco

September rainfall

September hourly sunshine

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 September 2018.

Other monthly averages

San Francisco weather stats

San Francisco weather statistics
Hottest month: September 21.4°C 70.5°F
Driest month: July 1mm 0ins
Sunniest month: April 11.1hrs
Coldest month: January 13.2°C 55.8°F
Wettest month: January 125mm 4.9ins
Map showing location of San Francisco (37.77493, -122.41942)

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