Should I start shopping for winter?

All summer I haven't really had much money put aside from bills to spend on myself. I'm behind on clothes but tbh I put it off this summer because I'm constantly working anyways. I'm a professional cleaner so I'm usually in sweats a shirt and my hair up with no makeup and my days off are spent cuddled up at home with my so.

Anyways I wanted to buy clothes but now that summer is like over should I start buying winter clothes? Or do you think it's too early?

Also could somebody tell me when it's suppose to start getting cold in the Northern California area?

Thank you!!