San Francisco weather

The best months to visit San Francisco are May, June, July, August. September-October is 'Indian Summer' when the fog retreats and the city sees its only real warm weather; Hardly Strictly Bluegrass fills Golden Gate Park.

September runs the highest averages in San Francisco, with typical daytime highs of 22°C (71°F). September heat waves hit 30C in the Mission and locals grab Bi-Rite ice cream and sit on Dolores Park's south slope; the Sunset stays 15 degrees cooler.

December brings the lowest averages, with daytime highs near 14°C (57°F). January nights drop to 5C and the Tenderloin steam vents draw crowds; sea lions on Pier 39 double as winter K-Mart migrants haul in from the Farallones.

December typically records the highest monthly rainfall — around 127mm on average. December-February bomb cyclones drop three inches in a day; Great Highway floods and 24th Street BART entrance becomes a waterfall.

San Francisco, United States has mild summers, mild winters, moderate seasonal rainfall. The fog has a name — Karl — and it belongs to Twitter. Neighborhoods change climate zones within blocks: Noe Valley bakes while the Outer Sunset shivers. Never call it 'San Fran' or 'Frisco' — locals will correct you to 'SF' or 'the city.' The Mission burrito is not a wrap; it's foil-swaddled and eaten from one end, and La Taqueria doesn't put rice in theirs, which is the whole argument. You can read the detailed month-by-month breakdown on this page.