Climate Insights for San Francisco

The climate in San Francisco is warm and mild. The average annual temperature is 19°C and approximately 809mm of precipitation falls per year. January is the wettest month, receiving around 113mm of rainfall. San Francisco is in the Southern Hemisphere. The seasons are reversed — summer runs from December to February, while winter falls between June and August. The summer months are: January, December, February. The coldest months are July, June, August, when temperatures can drop to 7°C.

Temperatures in San Francisco vary considerably across the year, with a 24°C difference between the coldest and warmest months. The warmest month is January, when average highs reach 31°C and the mean temperature sits around 25°C. July is the coolest month, with minimum temperatures around 7°C and an average of 12°C. On average, daily temperatures fluctuate by about 12°C between overnight lows and afternoon highs. The sharpest temperature change occurs between April and May, with a 4°C shift in average temperatures.

San Francisco is a moderately rainy area, receiving approximately 809mm of precipitation annually, which averages out to around 67mm per month. The wettest month is January, averaging 113mm of rainfall. February and April also tend to see above-average precipitation. The driest month is July, with just 16mm. That's 98mm less than January, 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 18km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is October, averaging 21km/h, noticeable enough to affect lighter outdoor activities. The calmest conditions occur in February, with average winds dropping to 16km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 5km/h between the calmest and windiest months.

It is currently autumn in San Francisco, which began on March 20, 2026. San Francisco is in the Southern Hemisphere, where the seasons are reversed — spring starts in September, summer in December, autumn in March, and winter in June. The warmest period peaks in January at around 31°C, while the coldest stretch bottoms out in July near 7°C. Winter is next, beginning on June 21, 2026 — 89 days from now.

The best time to visit San Francisco is during March, April, September, October, November and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 21°C with modest rainfall averaging 80mm per month. By contrast, January can be uncomfortably hot with highs reaching 31°C, while July is the coldest period with lows dropping to 7°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.