The weather in San Francisco is just like you see it in the movies: Expect fog, wind chill, and the occasional bout of darkness and showers. That being said, San Francisco is generally consistent, with temperatures ranging in the 50s to 60s almost entirely year-round. Summer comes in the fall (generally between October and November, which is called the "Indian Summer"). When those sunshine days do come and the air becomes a perfect 73 F, all of the students and folks of San Francisco couldn't be happier. You'll see students sunbathing and hanging out on all of the grassy areas of campus.
Because San Francisco State is so close to the ocean, the day can sometimes start out looking warm but change to cold and foggy very easily. Always come prepared with windbreakers, sweatshirts, or scarves. When it rains, it's usually for a week or two, but then it goes back to foggy and cool temperatures.