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- puttopalLv 52 decades agoFavorite Answer
It isn't as foggy as you might think. Spring and Fall are quite temperate, and San Francisco is renowned for it's "Indian Summer" in September. However, Mark Twain had a point when he said "The coldest Winter I ever spent was Summer in San Francisco."<br />
This is because the warm air from inland (where it gets quite hot in the Summer) clashes with the cold air from the surrounding Pacific Ocean and the SF Bay. When that happens, fog forms. Further explanation from http://kids.earth.nasa.gov/ "At night, the ground surface cools by radiating heat to space. Air near the ground cools to the dew point temperature, causing water in the air to condense."<br />
Sure it's cold, but fog can be quite beautiful and atmospheric. Just look at the pictures on http://www.goldengatephoto.com/sanfran/thefogrolls... Lovely!