Originally posted by Old Man Whirly!
That fits with what I experienced to be honest the only more obvious micro climate I have ever experienced is Barcelona.
It also doesn't get as cold at the lowest points of the year. eg I'm a 10-15 min drive North of the Golden Gate Bridge, when it's cold here at say 55f, SF will be a bit warmer.
SF's in a nigh permanent state of cool with the micro climate, why you see tourist freezing in their shorts and tank-tops during the summer, SF is a city where you want to wear layers unless you're used to the cold.
There was a heatwave 3ish years ago which I happened to be in SF at 11:00pm and it was humid in the low 80's, felt really weird.