San Francisco, CA Climate: Temperature & Rain by Month
Explore NOAA NCEI's 1991–2020 climate normals → and a clearly labeled PlainClimate comfort calculation
30-year climate normals (1991-2020) from San Francisco's primary NOAA station, SAN FRANCISCO INTL AP.
The climate verdict for San Francisco
Dryness leads the climate profile for San Francisco, California, with 19.6 inches of precipitation a year. NOAA records an annual average of 59°F. September is the warmest month at 65°F and January the coldest at 51°F.
- 59°F
- annual average temperature (NOAA normal)
- 19.6"
- yearly precipitation total
San Francisco: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USW00023234 · San Francisco, CA 59°F mean · 19.6" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-DRY · SWING-NARROW · COMF-UNK · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-MILD 59°F
- RANK-UPPER #4,871
- PHOTO-FINISH ≈ Santa Cruz
- PRCP-DRY 19.6"
- SWING-NARROW 14°F
- COMF-UNK Comfort n/a
- LOAD-HEAT 2,475 HDD
- STN-1 USW00023234
- BOOK-FULL 5/6 fields
Nearest mean-temperature peer: Santa Cruz, CA (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every CA station list.
- San Francisco (this station) 59°F
- Cold Berkeley, CA 59°F
- Hot Richmond, CA 59°F
- Near Santa Cruz, CA 59°F
- Near Santa Maria Pub…, CA 59°F
Climate Living Index · San Francisco
San Francisco: 80/100 · grade B
San Francisco publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals · NOAA hourly normals); 2 missing weights rescale to 100.
PlainClimate-derived for San Francisco, not an official NOAA rating. Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 0 calendar days | 100/100 · A |
| Summer moisture balance | 53.4°F mean dew point | 96/100 · A |
| Annual temperature balance | 58.7°F · 8.8° from 67.5°F | 72/100 · B |
| Precipitation balance | 19.6 in · 15.4 from 35 in | 46/100 · D |
San Francisco · 2026-08-04 · NOAA NCEI Climate Normals · method .
San Francisco is a temperate Köppen climate: Csb
Coldest-month mean 51.3°F and warmest-month mean 65.3°F place this station in temperate, dry-summer, warm summer climates (Csb). Class Csb is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: temperate, specifically temperate, dry-summer, warm summer.
- Köppen code
- Csb
- Group
- Temperate
- Warmest month
- 65.3°F
- Coldest month
- 51.3°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where San Francisco sits across the climate record
Three NOAA fields for San Francisco's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Top 29% warmest
- Among 6,861 stations, San Francisco sits in the warmer third of annual means.
- Annual precipitation
- Drier than 73%
- San Francisco's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- Narrower than 99%
- Warmest-to-coldest month gap for San Francisco is compact versus 6,861 complete station-years.
San Francisco's measured station temperature trend
MethodologyAcross 145 complete annual observations from 1851 to 2025, SAN FRANCISCO INTL AP warmed at a fitted rate of 0.14°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- San Francisco primary station fitted change +0.14 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 58°F (14°C) | 45°F (7°C) | 51°F (11°C) | 3.9" | 0.0 | 0.0 |
| February | 61°F (16°C) | 46°F (8°C) | 54°F (12°C) | 4.0" | 0.0 | 0.0 |
| March | 63°F (17°C) | 48°F (9°C) | 56°F (13°C) | 2.7" | 0.0 | 0.0 |
| April | 66°F (19°C) | 49°F (10°C) | 57°F (14°C) | 1.4" | 0.0 | 0.1 |
| May | 68°F (20°C) | 52°F (11°C) | 60°F (16°C) | 0.5" | 0.0 | 0.4 |
| June | 72°F (22°C) | 54°F (12°C) | 63°F (17°C) | 0.1" | 0.0 | 0.7 |
| July | 73°F (23°C) | 55°F (13°C) | 64°F (18°C) | 0.0" | 0.0 | 0.3 |
| August | 73°F (23°C) | 56°F (14°C) | 65°F (18°C) | 0.0" | 0.0 | 0.6 |
| September | 75°F (24°C) | 56°F (13°C) | 65°F (19°C) | 0.1" | 0.0 | 1.6 |
| October | 72°F (22°C) | 53°F (12°C) | 63°F (17°C) | 0.8" | 0.0 | 0.5 |
| November | 64°F (18°C) | 49°F (9°C) | 56°F (14°C) | 2.0" | 0.0 | 0.0 |
| December | 58°F (15°C) | 45°F (7°C) | 51°F (11°C) | 4.1" | 0.1 | 0.0 |
The year, day by day
The calendar barely moves in San Francisco: no date carries a normal high of 90°F or a normal low at freezing. The year runs between 44°F near January 1 and 75°F near September 15.
No freezing date
Not one calendar date in the 1991–2020 record carries a normal low at or below 32°F. The coldest normal low of the year is 44°F around January 1.
Where the wet dates fall
The likeliest wet date is February 18, when 38% of years recorded at least a hundredth of an inch. The driest is July 20 at 1%. Summed across the calendar, that is about 66 wet dates a year.
The widest day
September 28 carries the biggest normal gap between afternoon and dawn, 19°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for San Francisco.
Where San Francisco Stands Nationally
Among the steadiest day-night climates ranked: even the widest normal daily swing holds to roughly 19°F.
San Francisco earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall
10.9 days with precipitation
10.8 days with precipitation
10.3 days with precipitation
6.2 days with precipitation
3.3 days with precipitation
1.2 days with precipitation
0.0 days with precipitation
0.4 days with precipitation
0.9 days with precipitation
3.1 days with precipitation
7.2 days with precipitation
11.1 days with precipitation
San Francisco's wet season runs through the cold months
December, January and February carry 61% of the year's precipitation here, while June through August contribute 1%. That is the cool-season-dominant pattern of the West Coast and the higher inland West, where storm tracks swing south in winter and summer turns dry; the thermometer meanwhile shows an unusually narrow 14°F seasonal spread.
- Wettest month
- December, 4.1"
- Driest month
- July, 0.0"
- Wettest three months
- December, February, January (61% of the year)
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A cool-season label means the December-February share reaches 35%. Where snow falls, the monthly figures above report liquid-equivalent precipitation, so a wet winter month is not necessarily a rainy one.
How San Francisco's precipitation splits across the calendar
About 65 days a year record measurable precipitation here, carrying 19.6" between them, or roughly 0.30 inches on a typical wet day. That sits in the middle band: neither the many-light-days pattern of the Pacific Northwest and the Great Lakes, nor the few-heavy-events pattern of the Gulf and the desert Southwest.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year and say nothing about the heaviest single storm on record.
Frost Dates & Growing Season
First Fall Freeze
December 26
50% probability date
Last Spring Freeze
December 29
50% probability date
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
2,475
Higher = more heating needed
Cooling Degree Days
200
Higher = more cooling needed
Warmest Month
September
Coldest Month
January
Humidity & Wind
Monthly averages from hourly observations
| Month | Humidity | Wind (mph) | Clear Sky % | Overcast % |
|---|---|---|---|---|
| January | 78% | 7.1 | 19% | 28% |
| February | 74% | 9.1 | 16% | 25% |
| March | 71% | 11.3 | 18% | 18% |
| April | 69% | 13.2 | 21% | 15% |
| May | 72% | 13.8 | 18% | 15% |
| June | 72% | 13.1 | 23% | 12% |
| July | 76% | 12.5 | 12% | 17% |
| August | 72% | 11.6 | 26% | 9% |
| September | 69% | 10.0 | 32% | 11% |
| October | 70% | 8.0 | 28% | 15% |
| November | 73% | 7.1 | 24% | 22% |
| December | 77% | 6.9 | 20% | 28% |
Nationwide similar cities
Other rankable U.S. places outside CA closest to San Francisco on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (59°F here).
- Amarillo, TX 59°F · 0.0°F off
- Chesnee, SC 59°F · 0.0°F off
- Dyersburg, TN 59°F · 0.0°F off
- Forest City, NC 59°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (19.6" here), excluding temperature-peer places.
- Rolla, ND 19.6" · 0.0" off
- Pierre, SD 19.6" · 0.0" off
- Benkelman, NE 19.7" · 0.0" off
- Durango, CO 19.6" · 0.0" off
Data-derived climate profile
How San Francisco's climate pattern fits together
heating led · dry · low swing
Heating is the larger measured load in San Francisco, at 2,475 degree days versus 200 for cooling. Unlike a strongly continental record, however, its 14.0°F month-to-month range is compact; persistent cool-season demand matters more than a dramatic summer-to-winter reversal.
A frost-free growing-season length is not available for San Francisco. That missing field is kept separate from the observed temperature and precipitation record rather than filled from a regional estimate.
The calendar stays thermally compact and dry. September and January mark the typical warm and cold ends of the calendar, only 14.0°F apart, while the annual precipitation total remains below PlainClimate's dry threshold. The annual average is 59°F. The monthly rows show whether that limited precipitation is spread through the year or concentrated in a shorter interval.
San Francisco's cold-season load does not imply a wet climate. Annual precipitation is 19.6 inches, which places the station in PlainClimate's dry range. Snowfall is not added to the interpretation because its annual value is missing. The snowfall and rainfall fields should be read separately rather than inferred from temperature.
These labels group NOAA 1991-2020 normals from San Francisco's primary station, so the winter figures are a thirty-year average and not a floor: a single hard season can run well below them. Treat each band as a descriptive range for San Francisco, not an official NOAA class or a year-ahead forecast.
Questions about San Francisco's climate
How much rain does San Francisco get? ▼
How much energy does heating and cooling require in San Francisco? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from San Francisco's primary station: SAN FRANCISCO INTL AP (USW00023234). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 0667000). Match rule for San Francisco: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for San Francisco comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.