San Francisco is at its most pleasant from August to mid October. For walking, any time of year works. It is rarely warm enough for sunbathing.
When to go five ratings · thirty-six ten-day sections · click a cell to read it
Sun is not what San Francisco is for: the Sunbathing rating tops out at 17, mostly because it is too cool. The clearest skies come in October, when the sky is typically 21% covered at midday (mostly clear).
For being outside, go from August to mid October. It peaks in late August, at 73. Avoid early January for this: it falls to 5, mostly because it is too cold.
There is no bad time here for walking: it rates Good or better in every part of the year. It is at its best in mid November, at 82.
The year, measured
The average temperature in San Francisco over the whole year is 14°C. September is the hottest month, with highs of about 20°C; February is the coldest, with lows of about 9°C. The rainy (wet) season in San Francisco runs from October to May, peaking in March with a 88% chance of rain on a given day. The dry season is June to September; June is the driest month, at 43%. Winds in San Francisco are highest in June, averaging 3.7 m/s (13 km/h), and lightest in October, at 2.5 m/s (9 km/h). The prevailing wind is from the W. The clearest skies in San Francisco come in October, when the sky is typically 36% covered; January is the cloudiest month, at 51%.
Month by month San Francisco climate by month: average temperatures year round · click a month to read it
| Month | High | Low | Feels like | Chance of rain | Cloud | Wind | Being outside | Sun | Walking |
|---|---|---|---|---|---|---|---|---|---|
| January | 13°C | 9°C | 10°C | 88% | 51% | 2.8 m/s | 12 | 0 | 73 |
| February | 13°C | 9°C | 10°C | 88% | 37% | 3.2 m/s | 15 | 0 | 69 |
| March | 14°C | 9°C | 11°C | 88% | 49% | 3.3 m/s | 14 | 0 | 72 |
| April | 15°C | 10°C | 12°C | 87% | 41% | 3.4 m/s | 26 | 2 | 77 |
| May | 16°C | 12°C | 14°C | 86% | 44% | 3.6 m/s | 33 | 4 | 79 |
| June | 18°C | 13°C | 16°C | 43% | 38% | 3.7 m/s | 39 | 9 | 76 |
| July | 18°C | 14°C | 17°C | 51% | 47% | 3.5 m/s | 52 | 12 | 74 |
| August | 19°C | 15°C | 18°C | 50% | 48% | 3.1 m/s | 68 | 14 | 72 |
| September | 20°C | 14°C | 18°C | 59% | 41% | 2.8 m/s | 66 | 12 | 74 |
| October | 19°C | 13°C | 17°C | 81% | 36% | 2.5 m/s | 60 | 9 | 76 |
| November | 15°C | 10°C | 13°C | 87% | 37% | 2.5 m/s | 29 | 1 | 81 |
| December | 13°C | 9°C | 11°C | 88% | 46% | 2.7 m/s | 13 | 0 | 74 |
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short San Francisco weather by season
Year round, San Francisco has days of about 13°C at their warmest in January, its coolest month, and 20°C in September, its warmest; the coolest hours of the day run from 9°C to 15°C through the year, and the average temperature over the year is 14°C around the clock. Rain is most likely around March and least likely around June. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
San Francisco weather in winterDecember to February
Winter in San Francisco has typical daily highs of about 13°C and lows of about 9°C, with a 88% chance of rain on a given day.
San Francisco weather in springMarch to May
Spring in San Francisco has typical daily highs of about 15°C and lows of about 10°C, with a 87% chance of rain on a given day.
San Francisco weather in summerJune to August
Summer in San Francisco has typical daily highs of about 18°C and lows of about 14°C, with a 48% chance of rain on a given day.
San Francisco weather in autumnSeptember to November
Autumn in San Francisco has typical daily highs of about 18°C and lows of about 12°C, with a 76% chance of rain on a given day.
When is the rainy season in San Francisco?
The rainy (wet) season in San Francisco runs from October to May, peaking in March with a 88% chance of rain on a given day. The dry season is June to September; June is the driest month, at 43%.
What time of year is San Francisco windiest?
Winds in San Francisco are highest in June, averaging 3.7 m/s (13 km/h), and lightest in October, at 2.5 m/s (9 km/h). The prevailing wind is from the W.
What is the average temperature in San Francisco year round?
The average temperature in San Francisco over the whole year is 14°C. September is the hottest month, with highs of about 20°C; February is the coldest, with lows of about 9°C.
Where to go instead in early January, the weakest time here for being outside
How this is worked out
Every figure is a decade of weather-station observations blended into one typical year, in ten-day sections. The ratings, the chart and the feels-like column are read at midday local solar time. Being outside is the Easy outdoors rating, Sun is Sunbathing and Walking is Active outdoors, each out of 100: Good from 55, Ideal from 80. They describe what a time of year is usually like here, not a forecast. The dotted links open the map at that time of year; set its time of day to midday to see these numbers.