SF weather is awesome: ~50-75 all year round with specific neighborhoods that stay warm and sunny all the time if you're into that sort of thing. Heavenly compared to Pittsburgh, Boston, NYC, or DC.

The summer's are miserable with fog. It's as annoying as snow or sleet.

Bizarre claim. Also, avoiding fog is simple: move to a different neighborhood.

And let's not forget that DC during the latter part of summer is swamp-like, with high humidity and 80-90 degree weather. The city largely shuts down in August.