"The coldest winter I ever spent, was a summer in San Francisco." - Mark Twain
You can ALWAYS tell the tourists on the Golden Gate Bridge, when they walk around in shorts. Most locals know better- the tourists seem to get off a plane thinking SF will be like Hawaii. Not true. We've had great weather here and there, but overall, if environment is why you move to a city....SF is not the city for you.
And it's very expensive....try finding gas under $4.50 right now (especially at Chevron, Shell or 76). Rent is going to come down with the current market, but that's about the brightest spot on that front.