You know it’s winter in SF when:
The tourists arrive prepared for winter, instead of the usual t-shirt and shorts, that fuels sales at the fleece stalls down in Fisherman’s Wharf.
People are wearing ear muffs.
The butter you left on the counter to get soft gets hard every night.
You accidentally leave your heater on and you’re really happy that it’s still on when you get home.
You’re still asking that question: do I take my jacket off in the car or leave it on?
Beer is too cold. You’re constantly searching for Irish coffees or eggnogs at bars.
Your plants outside died due to a frost.
Your thoughts are preoccupied with plans for Tahoe after Christmas.
You’re in the sunshine, and still cold.
You get out of work, and it’s dark. You wake up, and it’s dark. You wonder who dropped you in the middle of short story where the girl gets trapped in the closet on a planet where it’s never sunny.
The public pools are oddly quiet.
You consider the act of staying warm exercise.
Despite the heater, your Victorian has a million drafts and you end up taking a shower/bath to get warm.
You find yourself actually listening to the NPR weather forecast