- San Francisco ›
- Weather by month
San Francisco Weather by Month
Average temperatures, rainfall and humidity for San Francisco, United States, month by month, built from OpenWeather's historical records. Use it to see what a typical San Francisco month looks like before you travel — then check the live San Francisco forecast for the days ahead.
Warmest month
September
25°C average high
Coolest month
December
8°C average low
Wettest month
December
100 mm of rain
Driest month
August
10 mm of rain
Average temperature and rainfall in San Francisco by month
Averages of the daily highs and lows recorded in each month, with total rainfall, mean humidity and mean wind speed.
| Month | Avg high | Avg low | Record low / high | Rainfall | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 15°C | 8°C | 1°C / 24°C | 76 mm | 76% | 12 km/h |
| February | 16°C | 8°C | 0°C / 24°C | 66 mm | 73% | 14 km/h |
| March | 17°C | 9°C | 2°C / 30°C | 61 mm | 74% | 15 km/h |
| April | 19°C | 10°C | 4°C / 31°C | 41 mm | 72% | 18 km/h |
| May | 20°C | 11°C | 7°C / 32°C | 26 mm | 75% | 19 km/h |
| June | 22°C | 13°C | 9°C / 36°C | 18 mm | 76% | 17 km/h |
| July | 23°C | 14°C | 10°C / 35°C | 15 mm | 79% | 15 km/h |
| August | 24°C | 14°C | 12°C / 36°C | 10 mm | 79% | 15 km/h |
| September | 25°C | 14°C | 10°C / 40°C | 11 mm | 77% | 14 km/h |
| October | 22°C | 13°C | 7°C / 37°C | 19 mm | 71% | 12 km/h |
| November | 18°C | 10°C | 2°C / 28°C | 48 mm | 73% | 11 km/h |
| December | 15°C | 8°C | -1°C / 22°C | 100 mm | 76% | 12 km/h |
Best time to visit San Francisco
The most comfortable time to visit San Francisco is generally July to September, balancing mild daytime temperatures against the driest stretch of the year. The city has a moderate seasonal swing and rain concentrates around December, totalling about 492 mm a year.
Travellers who prefer heat should aim for September, when highs average 25°C. December is the month to avoid if rain would spoil your plans — it averages 100 mm, roughly 10× the rainfall of August.
Source: OpenWeather historical and statistical weather data. Values are long-term averages, not a forecast — see the San Francisco forecast for what is happening now.