San Francisco weather by month & the best time to visit
United States · major city break · oceanic / maritime climate
The best time to visit San Francisco is September — its sunniest month (Sunshine Score 87/100), with October and August close behind. San Francisco averages about 2,879 hours of sunshine a year. Daytime highs around 19°C / 66°F and roughly 4 mm of rain in September.
When is the best time to visit San Francisco?
For sunshine, the best time to visit San Francisco is September, then October and August. The dullest month is January (33/100, 88 mm of rain). The full month-by-month picture is in the table below.
How sunny is San Francisco?
San Francisco gets a lot of sun: around 2,879 hours a year. 54 Sunshine Score points separate September (87) from January (33), so the month you pick matters. It ranks #104 of 580 destinations in United States for annual sunshine, above the national median of 2,279 hours. Rain has a clear season: the wettest stretch, around January, carries about 57% of the annual 515 mm.
Sunshine Score by month
| Month | Score | Day high | Night low | Rain | UV | Sea |
|---|---|---|---|---|---|---|
| January | 33 | 13° / 55°F | 9° / 48°F | 88 mm | 2 | 13° / 55°F |
| February | 40 | 14° / 57°F | 9° / 48°F | 88 mm | 3 | 14° / 57°F |
| March | 41 | 14° / 57°F | 10° / 50°F | 74 mm | 5 | 14° / 57°F |
| April | 52 | 15° / 59°F | 10° / 50°F | 38 mm | 7 | 14° / 57°F |
| May | 54 | 15° / 59°F | 11° / 52°F | 17 mm | 8 | 14° / 57°F |
| June | 71 | 17° / 63°F | 12° / 54°F | 6 mm | 9 | 15° / 59°F |
| July | 72 | 17° / 63°F | 13° / 55°F | 2 mm | 9 | 17° / 63°F |
| August | 80 | 18° / 64°F | 14° / 57°F | 2 mm | 8 | 17° / 63°F |
| September | 87 | 19° / 66°F | 14° / 57°F | 4 mm | 6 | 17° / 63°F |
| October | 84 | 19° / 66°F | 13° / 55°F | 26 mm | 5 | 16° / 61°F |
| November | 57 | 16° / 61°F | 11° / 52°F | 55 mm | 3 | 13° / 55°F |
| December | 37 | 14° / 57°F | 9° / 48°F | 115 mm | 2 | 13° / 55°F |
Sea temperature in San Francisco by month
The sea off San Francisco is warmest in July at around 17°C / 63°F, and coolest in January at 13°C / 55°F. It never reaches comfortable swimming temperatures (21°C+). Month-by-month sea-surface temperatures are in the Sea column of the table above.
Nearest destinations
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Head-to-head
How San Francisco compares month by month: San Francisco vs Sacramento · San Francisco vs Fresno · San Francisco vs Santa Rosa · San Francisco vs Monterey · all comparisons
San Francisco: questions and answers
What kind of destination is San Francisco?
San Francisco is a major city break in United States with a oceanic / maritime climate — the sea reaches 17°C at its warmest.
How many hours of sunshine does San Francisco get a year?
San Francisco gets about 2,879 hours of sunshine a year, at its best around September.
When is the best time to visit San Francisco?
The sunniest time to visit San Francisco is September, when the Sunshine Score peaks at 87/100 (with October and August close behind). Expect daytime highs around 19°C / 66°F.
What is the least sunny month in San Francisco?
January is the least sunny month in San Francisco, scoring 33/100 with about 88 mm of rain.
What is the sea temperature in San Francisco?
The sea in San Francisco ranges from about 13°C (January) to 17°C (July). Month-by-month sea temperatures are on this page.
How strong is the sun in San Francisco?
The typical midday UV index in San Francisco peaks around 9 (very high) in June, easing to about 2 (low) in January. Month-by-month midday UV values are in the UV column of the table on this page.
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