San Francisco's weather is not what you expect from California. Mark Twain never actually said "the coldest winter I ever spent was a summer in San Francisco," but whoever did had a point. Summer fog rolls through the Golden Gate most mornings from June to August, keeping temperatures in the low 60s (15-17C) while the rest of California bakes. Microclimates are extreme -- the Mission can be sunny and warm while the Sunset District is buried in grey.
The warmest, clearest months are September and October, when the fog retreats and the city basks in its Indian summer. This is the best time to visit if you want blue skies and comfortable temperatures. Spring (March to May) is mild and often sunny, with wildflowers in the Marin Headlands.
Winter (November to February) brings rain but rarely extreme cold -- temperatures hover around 50-55F (10-13C). The city is less crowded and hotel prices drop. December is festive, and the rain makes Golden Gate Park lush and green.
What to pack: Layers, always. A light jacket or sweater is essential year-round, even in summer. The temperature can drop ten degrees between neighborhoods. Comfortable walking shoes for the hills are non-negotiable.
Events worth timing a trip around: - Chinese New Year Parade (February) -- the largest outside Asia, running through Chinatown since 1860 - Bay to Breakers (May) -- a 12K footrace across the city that doubles as a moving costume party - Pride (late June) -- one of the biggest LGBTQ celebrations in the world, centred on the Castro and Civic Center - Hardly Strictly Bluegrass (October) -- a massive free music festival in Golden Gate Park - Fleet Week (October) -- Blue Angels over the Bay, best watched from Crissy Field or the Marina Green