San Francisco, CA Weather
San Francisco hourly forecast: next 24 hours
Today's high of 68°F (20°C) is right in line with the typical August high of 68°F (20°C).
Current conditions in detail
San Francisco weather tomorrow (Friday, August 28)
Tomorrow in San Francisco looks overcast, with a high of 63° and an overnight low of 59°. Precipitation chance is modest at 16%. Winds top out near 16 mph, and the UV index reaches 5 (moderate).
San Francisco 14-day forecast
About the weather in 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).
San Francisco weather: 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.
Season by season
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.
Average temperatures in San Francisco by month
| 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% |