I think JoBob summed it up (and made me laugh!). I love this area and February can produce some of the most memorable rides! But we had a sales bootcamp in Feb once and a friend from Mass came out to visit - we decided we wanted to walk the Golden Gate. The problem - we hit the bridge about the same time one of those lovely downpours started. We each had rain coats on, but we walk about half way across the bridge and ran back - we were wringing out our pants legs when we got back. Fortunately, we were able to get some great clam chowder on Fisherman's wharf, so we warmed up right quick. :P

I also remember a friend coming out in January and we had one of the best mountain bike rides ever. The trails were clear, the skies that incredible blue you usually only see at altitude and everything was sooo green! It is a crap shoot. Unfortunately, we seem to be getting drier every year, so you might just luck out. Either way, San Francisco is a beautiful city. You'll love it. But if you want fun in the sun, head to Florida.