alt Hacker NewsI grew up in northern Sweden. You're definitely miserable even when dressed perfectly in -15°C!
You're right that once it gets over +30°C or so, you'll be miserable whatever you wear. But there is a large temperature range below that that is wonderful. The Bay Area is almost always in that zone.
It's currently above freezing, dark, and wet here in Norway about 40 km south of Oslo. I'd be a lot more comfortable if it were -15 C. The sun would probably shine for more of the day instead of being hidden behind dark clouds and it would be dry; going for a walk would be much more enjoyable.