Down in Southern Cal, in the LA, San Diego areas it's usualy around 70ish in november rainy days are very rare even in winter. Up in northern cal, SF, might be a tad different... they have higher rainfall yearly figures than we do and their weather changes very very quickly. It can be fine at noon without a cloud in sight then later on that evening it's raining and cold. Go ahead and visit SF anyways... it's a great city, it has plenty of things to see/do even if it drizzles a little.