Climate Chart of San Francisco, USA
Monthly data: Temperature °C, Rain (mm), Sunshine (h) · 2013–2023
For San Francisco, USA, the climate data describe 2013–2023. Monthly mean temperatures average 13.7 °C across the calendar months, with the coolest monthly mean in January at 10.2 °C and the warmest in September at 17.3 °C. The figures sketch a moderate annual temperature range, while rainfall and sunshine vary across the year. These averages help frame the broad pattern, but they do not describe every day's conditions or guarantee what a visitor will encounter.
Climate overview
Temperature
Monthly mean temperature reaches its lowest point in January, at 10.2 °C, and its highest in September, at 17.3 °C. Those figures describe averages for each month, not daytime highs; individual days can differ from the monthly mean. The unweighted mean of the monthly means is 13.7 °C, a compact reference for the annual pattern rather than a day-weighted annual average.
Rain
Mean daily rainfall is lowest in August, at 0.01 mm/day, and highest in December, at 4.28 mm/day. These are average daily amounts, not monthly totals, and the low monthly mean does not guarantee rain-free days or indicate how often rain falls. Across the calendar months, the unweighted mean of monthly daily-rainfall means is 1.51 mm/day; it is a summary, not a day-weighted annual figure.
Sunshine
Average daily sunshine reaches its highest monthly mean in June, at 12.84 hours/day, and its lowest in December, at 6.30 hours/day. These are estimates of sunshine duration per day, not measures of day length, and actual conditions can vary. The unweighted mean across monthly sunshine means is 9.97 hours/day, offering a broad annual reference rather than a day-weighted average.
Best Travel Time Guide for San Francisco, USA: Ideal Seasons and Weather Insights
Visitors prioritising lower average rainfall could consider August, when mean daily rainfall is 0.01 mm/day; this is a criterion-based option, not a promise of dry weather or a measure of rain frequency. For planning that accounts for wetter averages, December has the highest mean daily rainfall, 4.28 mm/day, so carrying rain protection is a sensible precaution. Neither figure tells you the rainfall on a particular day. For visitors who prefer cooler monthly averages, January is the relevant reference point, with a monthly mean of 10.2 °C; pack for variable daily conditions rather than treating that average as a daytime temperature. Sunshine duration can also inform outdoor plans: June has the highest mean at 12.84 hours/day, while December has the lowest at 6.30 hours/day. These daily averages do not establish day length or guarantee sunshine, and the different criteria do not combine into a single best month to visit.
Climate Data Overview for San Francisco, USA
Explore the comprehensive climate data for San Francisco, USA. This detailed table provides valuable insights into temperature variations, precipitation levels, and seasonal changes, helping you understand the unique weather patterns of this region.
| Month | Average: Temperature °C | Rain (mm) / day | Snow (mm) / day | Sunshine (h) / day |
|---|---|---|---|---|
| Jan | 10.2 | 3.40 | 0.00 | 6.92 |
| Feb | 10.9 | 3.08 | 0.00 | 8.34 |
| Mar | 11.8 | 2.85 | 0.00 | 9.07 |
| Apr | 12.9 | 1.08 | 0.00 | 11.02 |
| May | 14.0 | 0.44 | 0.00 | 12.22 |
| Jun | 15.6 | 0.09 | 0.00 | 12.84 |
| Jul | 15.9 | 0.02 | 0.00 | 12.66 |
| Aug | 16.7 | 0.01 | 0.00 | 11.77 |
| Sep | 17.3 | 0.12 | 0.00 | 11.03 |
| Oct | 16.1 | 0.99 | 0.00 | 9.40 |
| Nov | 12.8 | 1.72 | 0.00 | 8.02 |
| Dec | 10.3 | 4.28 | 0.00 | 6.30 |
| Average | 13.7 | 1.51 | 0.00 | 9.97 |
