This is the Bay Area, so the weather here is generally nice. In the winter, there is rain and wind, but it never really snows, and it doesn't get below freezing ever here. While spring is always flip-flopping between being very warm and raining, the summer is always very nice. It is the nicest time here and is one of the longest seasons.
In San Francisco, it tends to be foggy and a little bit colder due its location closer to the ocean, but because of that, it never snows there, either.