San Francisco, CA Climate & Monthly Averages
The climate of San Francisco
Located in California, United States, San Francisco experiences a oceanic climate with mild temperatures year-round with regular rainfall. Afternoon temperatures peak near 70°F (21°C) in September and dip to about 56°F (14°C) in December, with around 22.9 inches (581 mm) of precipitation falling across the year.
Climate quick facts
- Hottest month: September - highs near 70°F (21°C)
- Coldest month: December - highs near 56°F (14°C)
- Record high: 101°F (38°C) · Record low: 33°F (0°C) (2015–2024)
- Wettest month: December (10 rainy days) · Sunniest: June (13.3 h sun/day)
- Climate type: oceanic - mild temperatures year-round with regular rainfall
Temperatures through the year
The warmest stretch of the year centers on September. Highs average 70°F (21°C) and overnight lows stay near 58°F (14°C). The coolest month is December, with typical highs of 56°F (14°C) and lows around 46°F (8°C). Based on 2015–2024 weather data, temperatures have reached as high as 101°F (38°C) and dropped as low as 33°F (0°C).
Rain, sun and snow
December is usually the wettest month. It brings about 5.1 inches (129 mm) of rain over 10 days, while August is the driest. June brings the most sunshine, averaging 13.3 hours of sun a day.
Monthly climate table
| Month | High | Low | Rain days | Precipitation | Sunshine | Humidity |
|---|---|---|---|---|---|---|
| January | 57° | 46° | 10 | 4.9 in | 7.0 h/day | 83% |
| February | 59° | 46° | 8 | 3.5 in | 8.9 h/day | 78% |
| March | 59° | 48° | 10 | 3.7 in | 9.4 h/day | 78% |
| April | 61° | 50° | 5 | 1.3 in | 11.4 h/day | 77% |
| May | 63° | 52° | 2 | 0.7 in | 12.7 h/day | 77% |
| June | 67° | 55° | 0 | 0.1 in | 13.3 h/day | 76% |
| July | 67° | 56° | 0 | 0.0 in | 13.1 h/day | 80% |
| August | 68° | 58° | 0 | 0.0 in | 12.3 h/day | 81% |
| September | 70° | 58° | 1 | 0.1 in | 11.4 h/day | 77% |
| October | 69° | 55° | 3 | 1.1 in | 9.8 h/day | 74% |
| November | 62° | 50° | 7 | 2.3 in | 8.5 h/day | 77% |
| December | 56° | 46° | 10 | 5.1 in | 6.7 h/day | 81% |
San Francisco month by month
San Francisco weather in January
January brings highs around 57°F (14°C), lows near 46°F (8°C), about 10 wet days.
San Francisco weather in February
February brings highs around 59°F (15°C), lows near 46°F (8°C), about 8 wet days.
San Francisco weather in March
March brings highs around 59°F (15°C), lows near 48°F (9°C), about 10 wet days.
San Francisco weather in April
April brings highs around 61°F (16°C), lows near 50°F (10°C), about 5 wet days.
San Francisco weather in May
May brings highs around 63°F (17°C), lows near 52°F (11°C), about 2 wet days.
San Francisco weather in June
June brings highs around 67°F (19°C), lows near 55°F (13°C), about 0 wet days - typically the sunniest month of the year in San Francisco.
San Francisco weather in July
July brings highs around 67°F (19°C), lows near 56°F (13°C), about 0 wet days.
San Francisco weather in August
August brings highs around 68°F (20°C), lows near 58°F (14°C), about 0 wet days - typically the driest month of the year in San Francisco.
San Francisco weather in September
September brings highs around 70°F (21°C), lows near 58°F (14°C), about 1 wet days - typically the hottest month of the year in San Francisco.
San Francisco weather in October
October brings highs around 69°F (21°C), lows near 55°F (13°C), about 3 wet days.
San Francisco weather in November
November brings highs around 62°F (16°C), lows near 50°F (10°C), about 7 wet days.
San Francisco weather in December
December brings highs around 56°F (14°C), lows near 46°F (8°C), about 10 wet days - typically the coldest month and the wettest month of the year in San Francisco.
Seasons in San Francisco
Spring (March through May)
Spring in San Francisco is crisp but comfortable, with daytime highs averaging 61°F (16°C) and nights around 50°F (10°C); rain falls on about 17 days over the three months.
Summer (June through August)
Summer in San Francisco is crisp but comfortable, with daytime highs averaging 67°F (20°C) and nights around 56°F (13°C); precipitation is infrequent.
Fall (September through November)
Fall in San Francisco stays on the cool side of mild, with daytime highs averaging 67°F (19°C) and nights around 54°F (12°C); rain falls on about 10 days over the three months.
Winter (December through February)
Winter in San Francisco is crisp but comfortable, with daytime highs averaging 57°F (14°C) and nights around 46°F (8°C); expect showers on roughly 28 days across the season.
Climate questions, answered
What is the average temperature in San Francisco?
Is San Francisco hot in summer?
Is San Francisco cold in winter?
How many rainy days does San Francisco get in a year?
Best time to visit San Francisco
The best time to visit San Francisco is generally April to September, when warm days, manageable rainfall and plenty of daylight line up. Daytime temperatures in that window typically sit near 66°F (19°C).
Pack for San Francisco with a warm jacket and layers for the cooler season; rain gear if you travel around December. Evenings can feel noticeably cooler than afternoons - September nights average 58°F (14°C).
San Francisco temperature records (2015-2024)
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ.