The climate in San Francisco during December can be summarized as mild and a little damp.
December is in the winter in San Francisco and is typically the 2nd coldest month of the year. Daytime maximum temperatures average around a cool 14°C (57°F), whilst at night 7°C (45°F) is normal.
|Daytime temperature||13.7°C 56.6°F|
|Nightly temperature||7.2°C 44.9°F|
|Average temperature||10.4°C 50.7°F|
|Daily sunshine||5.7 hrs|
|Avg rainfall||97 mm 3.8 ins|
|Rainy days||10 days|
|Sea temperature||12.7°C 54.9°F|
|Windspeed||12.6kph 8 mph|
On average December is the 2nd wettest month of the year in San Francisco with around 97mm 3.8 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 10 days, although this may vary considerably.
On the flip side this corresponds to an average of 5.7 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 December 2020.
|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|