As a Northern Californian (from Davis, Ca about an hour and a half north of SF) I’ll tell you what winters are like in my part of the state.
Usually pretty mild compared to other places. Cold and dry in the beginning, then cold and wet in the later months. Our rain started late this year though. The rain isn’t bad at all, unless it’s mixed with wind. The wind is what sucks. The temperature ranges from 50s to 60s during the day and roughly around the 40s in the nights. Not usually cold enough to leave ice on the roads, but you will get frost on your car and lawn.
Where I live, we rarely get snow. When we do get snow it’s more like slush, but exciting for us all the same. Last time it “snowed” was this past December (when I was in Tennessee and missed it.. just my luck). Before that, the last time it snowed was in 2002.