In general, San Francisco’s weather is mild and fairly comfortable year-round, though the frequent fog and coastal winds make it colder than many people imagine. As in most of the U.S., December-February are the coldest months, with temperatures mostly in the 40s and 50s. It rarely snows in San Francisco, but winter is the rainiest time of year. Unlike the rest of the U.S., however, the city’s warmest month is September, though highs are still just around 72.