San Francisco, CA Climate & Monthly Averages
The climate of San Francisco
San Francisco runs on a dry-summer rhythm: the warmest months are also the driest. August averages less than 1 mm while the wet season peaks in December at 5.1 inches (129 mm). Highs range from 56°F (14°C) to 70°F (21°C).
Climate quick facts
- Hottest month: September - highs near 70°F (21°C)
- Coldest month: December - highs near 56°F (14°C)
- Decade extremes (2015-2024): 101°F (38°C) high · 33°F (0°C) low
- Wettest month: December (10 rainy days) · Sunniest: June (13.3 h sun/day)
- Climate type: oceanic
- Annual swing: 7°C between the average warmest and coolest month · day to night: 6°C
- Average humidity: 78%
Temperatures through the year
September is the warm end of the year, averaging 70°F (21°C) by day and 58°F (14°C) overnight. December bottoms out at 56°F (14°C) in daylight, 46°F (8°C) after dark. Across the gridded 2015-2024 daily record, the highest daily maximum for this location was 101°F (38°C) and the lowest daily minimum 33°F (0°C). 5 months average under 20 mm of rain, the longest unbroken stretch running May through September.
Rain, sun and snow
The wettest month is December (5.1 inches (129 mm) across 10 days) and the driest August. Between the average September and the average December lie 7°C, a narrower spread than about 81% of the cities we track.
How San Francisco compares
- 59% of the year's precipitation falls in its wettest three months - more seasonal than 91% of the 3496 cities we track.
- Afternoons run 6°C above the following night - a flatter daily curve than all but 11% of the 3496 cities we track.
- Rain or snow reaches the ground on 56 days a year - fewer wet days than all but 11% of the 3496 cities we track.
Ranked against every city in our dataset, each measured on the same ten-year window.
Monthly climate table
| Month | High | Low | Rain days | Precipitation | Sunshine | Daylight | Wet-day chance | Humidity |
|---|---|---|---|---|---|---|---|---|
| January | 57° | 46° | 10 | 4.9 in | 7.0 h/day | 9.8 h | 34% | 83% |
| February | 59° | 46° | 8 | 3.5 in | 8.9 h/day | 10.7 h | 27% | 78% |
| March | 59° | 48° | 10 | 3.7 in | 9.4 h/day | 11.8 h | 32% | 78% |
| April | 61° | 50° | 5 | 1.3 in | 11.4 h/day | 13.1 h | 15% | 77% |
| May | 63° | 52° | 2 | 0.7 in | 12.7 h/day | 14.2 h | 8% | 77% |
| June | 67° | 55° | 0 | 0.1 in | 13.3 h/day | 14.8 h | 1% | 76% |
| July | 67° | 56° | 0 | 0.0 in | 13.1 h/day | 14.5 h | 1% | 80% |
| August | 68° | 58° | 0 | 0.0 in | 12.3 h/day | 13.6 h | 1% | 81% |
| September | 70° | 58° | 1 | 0.1 in | 11.4 h/day | 12.4 h | 3% | 77% |
| October | 69° | 55° | 3 | 1.1 in | 9.8 h/day | 11.1 h | 9% | 74% |
| November | 62° | 50° | 7 | 2.3 in | 8.5 h/day | 10.1 h | 22% | 77% |
| December | 56° | 46° | 10 | 5.1 in | 6.7 h/day | 9.6 h | 32% | 81% |
San Francisco month by month
Average high and low for each month, with the bar showing where it sits in San Francisco's year (left is the coldest night, right is the warmest afternoon).
January
- Rain
- 10 days
- Sunshine
- 7.0 h
- Daylight
- 9.8 h
February
- Rain
- 8 days
- Sunshine
- 8.9 h
- Daylight
- 10.7 h
March
- Rain
- 10 days
- Sunshine
- 9.4 h
- Daylight
- 11.8 h
April
- Rain
- 5 days
- Sunshine
- 11.4 h
- Daylight
- 13.1 h
May
- Rain
- 2 days
- Sunshine
- 12.7 h
- Daylight
- 14.2 h
June
- Rain
- 0 days
- Sunshine
- 13.3 h
- Daylight
- 14.8 h
July
- Rain
- 0 days
- Sunshine
- 13.1 h
- Daylight
- 14.5 h
August
- Rain
- 0 days
- Sunshine
- 12.3 h
- Daylight
- 13.6 h
September
- Rain
- 1 day
- Sunshine
- 11.4 h
- Daylight
- 12.4 h
October
- Rain
- 3 days
- Sunshine
- 9.8 h
- Daylight
- 11.1 h
November
- Rain
- 7 days
- Sunshine
- 8.5 h
- Daylight
- 10.1 h
December
- Rain
- 10 days
- Sunshine
- 6.7 h
- Daylight
- 9.6 h
Warmer places to go, by month: January · February · March · April · May · June · July · August · September · October · November · December
Seasons in San Francisco
Spring (March through May)
Spring in San Francisco stays on the cool side of mild, with daytime highs averaging 61°F (16°C) and nights around 50°F (10°C); rain comes on about 17 days over the three months. Daylight is generous - around 11.2 hours of sun a day.
Summer (June through August)
Summer in San Francisco runs cool rather than cold, with daytime highs averaging 67°F (20°C) and nights around 56°F (13°C); precipitation is essentially absent. Daylight is generous - around 12.9 hours of sun a day.
Fall (September through November)
Through fall, San Francisco stays on the cool side of mild: 67°F (19°C) by day, 54°F (12°C) after dark, and rain comes 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
When is the dry season in San Francisco?
How much sun does San Francisco get?
Is San Francisco hot in summer?
Is San Francisco humid?
What is the average temperature in San Francisco?
What should I wear in San Francisco?
Best time to visit San Francisco
April to September is the sweet spot for San Francisco - the dry season is running but the afternoons are still bearable. Expect 66°F (19°C) in the afternoon and around 1 days of rain in a typical month of it. For the same question asked the other way round, see where else is warm in April.
Pack for San Francisco with a warm jacket and layers for the cooler season and rain gear if you travel around December. Note the gap between afternoon and night: September pairs 70°F (21°C) with 58°F (14°C).
San Francisco temperature records (2015-2024)
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ. Need the precipitation in other units? The mm-to-inches rainfall converter handles it.