Climate Overview
The climate in San Francisco is hot. The average annual temperature is 28°C and approximately 2494mm of precipitation falls per year. San Francisco receives a notable amount of rainfall throughout the year, including during its driest month. San Francisco sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
San Francisco has relatively stable temperatures year-round, staying within a 10°C range. The warmest month is September, when average highs reach 33°C and the mean temperature sits around 28°C. February is the coolest month, with minimum temperatures around 23°C and an average of 27°C. Daily temperature variation is modest, with an average difference of 8°C between highs and lows.
Precipitation
San Francisco is a very wet location, receiving approximately 2494mm of precipitation annually, which averages out to around 208mm per month. The wettest month is January, averaging 252mm of rainfall. October and June also tend to see above-average precipitation. The driest month is March, with just 124mm. That's 128mm less than January, the wettest month. Rainfall is relatively evenly distributed throughout the year, so there is no pronounced dry or wet season to plan around.
Wind
San Francisco is relatively calm, with an average annual wind speed of 1km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is February, averaging 2km/h, though still comfortable for most outdoor activities. The calmest conditions occur in June, with average winds dropping to 1km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 1km/h gap between the calmest and windiest months.
Seasons
92 days until Autumn
It is currently summer in San Francisco, which began on June 21, 2026. San Francisco sits near the equator, so the traditional four-season cycle is less pronounced — temperatures remain relatively stable year-round. The warmest period peaks in September at around 33°C, while the coldest stretch bottoms out in February near 23°C. Autumn is next, beginning on September 23, 2026 — 92 days from now.
Spring
Temperatures range from 24 to 33°C. Rainfall is heavy, totalling around 471mm across the season with a monthly average of 157mm. Winds are generally light, averaging 2km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 25 to 33°C. Rainfall is heavy, totalling around 685mm across the season with a monthly average of 228mm. Winds are generally light, averaging 1km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 24 to 33°C. Rainfall is heavy, totalling around 658mm across the season with a monthly average of 219mm. Winds are generally light, averaging 1km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 23 to 31°C. Rainfall is heavy, totalling around 680mm across the season with a monthly average of 227mm. Winds are generally light, averaging 2km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Monthly Climate Data
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.
