Mark Twain once said, “If you don’t like the weather in New England, wait a few minutes.” In San Francisco, if you don’t like the weather, just drive a few miles. The temperature at both ends of the mile-long Golden Gate Bridge can be 20°F different. Since a city’s average temperature for the year is not helpful to travelers, here is a general breakdown of what to expect.
Autumn weather is the most dependable. Warm (80°F in The City, 90-100°F in the East, South or North bay cities) and dry “Indian Summer” days prevail in October, when there’s least likely to be any fog or rain. Still, it can be in the 50s at night. Some say this is the best time of year to visit The City, and that the real summer here happens in September & October.
For the most part, San Francisco’s weather is temperate and, within limits, predictable although it has its own micro climate. San Francisco temperatures seldom dip below 40°F, or reach or exceed 90°F. Its summers are famously foggy; but for the summer visitor who hasn’t heard, it’s important to know about The City’s “natural air conditioner” – the fog. But it gives tourists the excuse to buy a souvenir SF sweatshirt or scramble to buy a windbreaker. It can be in the 80s downtown, and then the fog rolls in in the afternoon, shaving 30 degrees off the top.
Article Courtesy of tripadvisor.com