San Francisco weather in December
Temperature, sea and sunshine in December: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in December
Fair
Best time to visit: April – October
What is the weather like in San Francisco in December?
In December, San Francisco is cool: daytime highs average 14 °C, and nights cool down to about 7 °C. The sea averages 12.1 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. Rain is frequent, with about 10 rainy days and 93 mm in total. All in all, December is a so-so month for a holiday in San Francisco.
December compared
How the weather changes from November to January. Tap a month to open it.
| NovemberNov | DecemberDec | JanuaryJan | |
|---|---|---|---|
| Score | 78 | 52 | 54 |
| Day | 17° | 14° | 14° |
| Night | 9° | 7° | 6° |
| Sea | 13° | 12° | 12° |
| Sun | 6 h | 5 h | 5 h |
| Rain days | 6 | 10 | 9 |
More details for December
- Daylight
- 9 h 34 min07:18 – 16:52
- UV index
- 2 · lowclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or more
- Wind
- 14 km/haverage daily peak
- Cloud cover
- 60 %on average
- Hot days
- 0 days30 °C or more
- Time zone
- UTC−8America/Los_Angeles
How the score comes together
- Temperatureweight 50 %56 %
- Sunshineweight 20 %30 %
- Few rainy daysweight 30 %59 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in December
- A jumper for the evenings
- Rain jacket or umbrella
San Francisco in December: quick answers
Is San Francisco hot in December?
No. In December, San Francisco is cool: daytime highs average 14 °C and nights drop to about 7 °C.
Can you swim in San Francisco in December?
Only if you don't mind cold water: in December the sea averages just 12.1 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in San Francisco in December?
Rain is frequent, with about 10 rainy days and 93 mm in total.
San Francisco month by month
The whole year in San FranciscoAll destinations: USAWhere to go in DecemberSea temperature in December
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0)