Here in Northern California we recently had our 4th driest December on record. Temperatures lately have been almost spring-like.
For a few days now, we've been prepared for a big storm blowing in from the Pacific. This morning the sky was overcast and temperatures were in the low 40s instead of their usual 30s, and this afternoon the first sprinkles came. This isn't a heavy rain by any stretch, but it's expected to be persistent--continuing off and on for the next week.
Winter has finally started in the Sacramento Valley.