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Climate in San Francisco, California: Monthly Weather Averages
San Francisco sits at 150 feet above sea level, and its climate, as recorded at the San Francisco Downtown, CA station, runs to a yearly mean of 57.7°F. The warmest month is September, averaging 62.9°F with typical highs of 70.2°F; the coldest is January, averaging 52.2°F with lows around 46.6°F. Across a normal year the city receives 22.9 in of precipitation. The full month-by-month picture below comes from the official 1991–2020 U.S. Climate Normals — the 30-year averages the National Weather Service itself uses — so it describes the San Francisco climate you should actually plan around, whether you are timing a visit, weighing a move, or just settling an argument about which month is best.
San Francisco climate month by month
The table below is the complete 1991–2020 normals profile for San Francisco: average high, average low and mean temperature, rainfall, and snowfall for every month. Read down the Mean column to feel the year's rhythm — San Francisco's temperature range runs from 52.2°F in January to 62.9°F in September.
| Month | Avg High (°F) | Avg Low (°F) | Mean (°F) | Rain (in) | Snow (in) |
|---|---|---|---|---|---|
| January | 57.8 | 46.6 | 52.2 | 4.40 | — |
| February | 60.4 | 47.9 | 54.2 | 4.37 | — |
| March | 62.1 | 48.9 | 55.5 | 3.15 | — |
| April | 63.0 | 49.7 | 56.4 | 1.60 | — |
| May | 64.1 | 51.4 | 57.8 | 0.70 | — |
| June | 66.5 | 53.0 | 59.7 | 0.20 | — |
| July | 66.3 | 54.4 | 60.3 | 0.01 | — |
| August | 67.9 | 55.5 | 61.7 | 0.06 | — |
| September | 70.2 | 55.6 | 62.9 | 0.10 | — |
| October | 69.8 | 54.4 | 62.1 | 0.94 | — |
| November | 63.7 | 50.7 | 57.2 | 2.60 | — |
| December | 57.9 | 47.0 | 52.5 | 4.76 | — |
| Year | 64.1 | 51.3 | 57.7 | 22.89 | — |
How to read the colors:below freezingcoldcoolmildwarmhot. Bands are colored by each cell's own temperature, so a whole year reads at a glance.
NOAA does not publish monthly snowfall normals for this station, so the snow column is shown as —; the temperature and precipitation normals for this station are complete.
San Francisco through the seasons
Winter in San Francisco averages highs of 57.8–60.4°F and lows of 46.6–47.9°F, a seasonal mean of 53.0°F. The three months together bring 13.5 in of precipitation — about 59% of the city's yearly total — with December the wettest of the three at 4.76 in. Winters here are cool rather than harsh: chilly mornings, mild afternoons, and only occasional brushes with freezing weather.
Spring in San Francisco averages highs of 62.1–64.1°F and lows of 48.9–51.4°F, a seasonal mean of 56.6°F. The three months together bring 5.5 in of precipitation — about 24% of the city's yearly total — with March the wettest of the three at 3.15 in. The season is a transition: the average temperature climbs 2.3°F from March to May, and by late spring San Francisco is firmly into mild territory.
Summer in San Francisco averages highs of 66.3–67.9°F and lows of 53.0–55.5°F, a seasonal mean of 60.6°F. The three months together bring 0.3 in of precipitation — about 1% of the city's yearly total — with June the wettest of the three at 0.20 in. Summer is the mildest in the country by big-city standards — heat waves happen, but the average afternoon stays in the 70s, and many homes historically get by without air conditioning.
Fall in San Francisco averages highs of 63.7–70.2°F and lows of 50.7–55.6°F, a seasonal mean of 60.7°F. The three months together bring 3.6 in of precipitation — about 16% of the city's yearly total — with November the wettest of the three at 2.60 in. Temperatures ease off through the season — the monthly mean drops 5.7°F from September to November — and fall is when San Francisco's weather turns crisp and dry, while nights stay mostly frost-free into December.
Best and worst months to visit San Francisco
Ranking every month by its normals — mild mean temperatures score best, heavy rain and snow count against — the most comfortable months to visit San Francisco are:
JulyAugustSeptember
July leads the list: average highs of 66.3°F, lows of 54.4°F, and 0.01 in of rain. The other picks, August and September, offer the same balance in San Francisco's mild stretch of the year. At the other end, December is usually the month to avoid — the year's heaviest rain, with a mean temperature of 52.5°F and 4.76 in of precipitation.
How San Francisco compares
Across the 114 cities in our dataset, the typical city averages 57.8°F for the year and 35.7 in of precipitation. San Francisco runs 0.1°F cooler than that typical city and drier by 12.8 in a year, ranking #52 of 114 for annual warmth and #81 of 114 for precipitation (wettest first). Its year-round temperature swing — warmest month minus coldest — is 10.7°F, which puts it in the mild, ocean- or latitude-softened camp.
Within California, San Francisco is #8 of 9 for warmth of the cities we track. See the California climate overview for the full state comparison, including Fresno (warmest, 65.0°F yearly mean) and Eureka (coolest, 52.6°F).
Planning notes for San Francisco
For anyone relocating: average lows never drop below freezing in any month, so hard freezes are events, not seasons; even the warmest month's average high stays below 80°F, so summer heat is rarely a planning factor; days and nights differ by only 12.9°F on average, a sign of strong water or coastal moderation; 9 months of the year average between 55°F and 80°F, the band most people find comfortable without heating or cooling. Those four facts, all straight from the normals table above, shape everything from a San Francisco wardrobe to its utility bills.
San Francisco climate FAQ
What is the warmest month in San Francisco?
September is the warmest month in San Francisco, with a mean temperature of 62.9°F, average highs of 70.2°F and average lows of 55.6°F (1991–2020 normals).
What is the coldest month in San Francisco?
January is the coldest month, averaging 52.2°F, with highs of 57.8°F and lows of 46.6°F.
How much rain does San Francisco get in a year?
San Francisco averages 22.89 in of precipitation a year. The wettest month is December (4.76 in) and the driest is July (0.01 in).
When is the best time of year to visit San Francisco?
By the normals, the most comfortable months are July, August, September — mild average temperatures with moderate rainfall. December is typically the least comfortable month.
Source: 1991–2020 U.S. Climate Normals, NOAA National Centers for Environmental Information (NCEI) — ncei.noaa.gov. Station: San Francisco Downtown, CA (USW00023272), elevation 150 ft. Figures checked October 2026.