LOL I know all about "90 in the city." A very rare event, you get 2.5 days, and the afternoon of the 3rd day, the freaking, freezing fog comes rolling back in.
I remember once, when I was a child, we had out of town guests, whom we'd advised what kind of clothes to bring. We were at Fisherman's Wharf, and noticed some uniformed tourists shivering in shorts.
As we passed them, my father quipped, "I'll bet you thought San Francisco was in sunny California!"