Here’s your year-round forecast for San Francisco: cool in the morning until the fog burns off, with afternoon temperatures reaching between 55°F and 70°F, then dropping as the sun sets or the fog rolls in, whichever happens first. Chances of precipitation are slight (though more likely December to March) and the likelihood of temperatures topping 80°F even slimmer (though spring through fall and the odd February, you can always hope). Not bad, really, as long as you don’t mind constantly dressing in layers and throwing some kind of fabulous coat or wrap over your obligatory parade ensemble – a feather boa can begin to seem mighty practical.
If you’re coming to San Francisco expecting endless summer and bikinis galore, think again. That’s San Francisco’s rival city-state of Los Angeles down south you’ve got in mind, and San Franciscans will show you no pity if you whine through chattering teeth about how this is supposed to be C-C-California. Consider yourself forewarned about the summer fog, which can lower temperatures and raise goose bumps in a hurry. The day might start out hot, but when inland summer heat draws the fog in from the sea, temperatures plummet and the wind picks up. San Franciscans take consolation in mild winters, when the contrast between land and sea temperatures is less extreme, the fog less frequent and the weather more reliable.
Microclimates add a touch of magic realism to San Francisco: when it’s foggy and drizzling in the outer reaches of the Sunset, it may be bright and sunny in the Mission. The sunniest spots in town are nestled in the protective cover of hills, and you can witness clouds bounding through low-lying areas like Golden Gate Park and wander into hairdo-altering wind tunnels on the eastern shore of the Bay. If you don’t like the weather in one part of the city, try hopping on Muni for a different climate. You can feel the climate shift on east–west routes like the N Judah, from windswept reaches of downtown through the sunny pocket of Duboce Park and the Castro to the often foggy, blustery Ocean Beach. North–south routes such as the 22 Fillmore can take you from a misty Marina to a quick peek over the clouds in Pacific Heights, before descending to a foggy Haight, through the sunny Mission and Potrero, and all the way to a windswept waterfront.