California. It's so big and diverse it's hardly a fair comparison. If it were on the east coast it would be 12 states. No matter what kind of terrain or scenery you like, it's in California.
And if you get a windbreaker you're set for 12 months of riding out of the year. Contrary to what ToC coverage implies, even rain isn't much of a problem in the winter, and 55 and rain sounds pretty nice in a lot of states in January. Although like everthing else, the temperature depends on where you are. I did most of my riding in Ventura and Santa Barbara counties, with some around Napa valley, no need to stop riding or get special gear all year long.