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.
|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|
|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.
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 2019.
|Hottest month:||September||21.4°C 70.5°F|
|Driest month:||July||1mm 0ins|
|Coldest month:||January||13.2°C 55.8°F|
|Wettest month:||January||125mm 4.9ins|