california in MAY?
 

We can afford only one vacation a year and we always go where I love. next year he would like to go to Calif. Fly from Boston to S.F. and pick up a car, see napa, Sonoma big sur and perhaps it would be in May. Will the weather be warm. Do you wear summer clothes?

It's variable. Chances are good the weather will be moderate, high 60's to mid 70's at that time of year, but we can have heat waves or even a shower. A cardigan should do it. By the way, the temperature can even be quite different in SF versus Sonoma or Napa.

By Boston standards, yes, you wear summer clothes! Expect SF to be high 50s and 60s and Napa is generally 10 degrees warmer than the city. I would plan on a lightweight wool blazer for night in SF, long sleeve shirt with possible cotton sweater in the city. Cotton or dark linen slacks, not cords.Possibly pack one cotton turtleneck. No heavy duty wools as you would wear in Boston winters. No shorts!! T-shirts are not quite warm enough at that time of year unless layered under other shirts. It's a good time to have a fleece vest to wear over other things and take off in the middle of the day. The rains should be over and the kids are not yet out of school. Good time to visit the Bay area. The very best time is probably late September, early October, but May is pretty good.

Ditto the above re: clothing & termperature. Our hills are at their lovliest in May - GREEN and lots of wildflowers. Please go hiking in the hills around the SF Bay area! The fog usually hasn't started yet.

average temp at that time is low to mid 60's and average rainfall is 1/2"