Climate Insights for San Francisco

The climate in San Francisco is warm and mild. The average annual temperature is 25°C and approximately 2346mm of precipitation falls per year. San Francisco receives a notable amount of rainfall throughout the year, including during its driest month. San Francisco is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: June, May, August. The coldest months are January, February, December, when temperatures can drop to 21°C.

San Francisco has relatively stable temperatures year-round, staying within a 7°C range. The warmest month is June, when average highs reach 28°C and the mean temperature sits around 26°C. January is the coolest month, with minimum temperatures around 21°C and an average of 23°C. Daily temperature variation is modest, with an average difference of 4°C between highs and lows.

San Francisco is a very wet location, receiving approximately 2346mm of precipitation annually, which averages out to around 196mm per month. The wettest month is November, averaging 400mm of rainfall. October and December also tend to see above-average precipitation. The driest month is April, with just 67mm. That's 334mm less than November, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.

San Francisco is mildly breezy, with an average annual wind speed of 16km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is July, averaging 19km/h, though still comfortable for most outdoor activities. The calmest conditions occur in October, with average winds dropping to 13km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 6km/h gap between the calmest and windiest months.

It is currently spring in San Francisco, which began on March 20, 2026. San Francisco is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in June at around 28°C, while the coldest stretch bottoms out in January near 21°C. Summer is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit San Francisco is during March, when the weather is most comfortable for travellers. During these months, average temperatures hover around 24°C with modest rainfall averaging 87mm per month. By contrast, June can be uncomfortably hot with highs reaching 28°C, while January is the coldest period with lows dropping to 21°C. Despite being the best months overall, some rain is still likely — pack a waterproof layer and plan a mix of indoor and outdoor activities.

The table below shows monthly climate averages for San Francisco based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.