Ahh, no I don't ride in the winter... any part of the winter. Usually I'll get a few rides in during December and I start again March. Well, if it gets to 40 I'll ride my road bike if the roads are OK and I'll ride my hybrid down to about 35; same with the mtb. But that's not commuting. I'm a teacher and I have to be at work early, so I leave at 5:30 to 5:45. Since I commute on my road bike, which does not support a light, because I have ergonomic carbon bars, I really only commute about 6-8 weeks out of the year. And that will be over when school is out, because I am going back to school in the fall and I will be taking the train into Cambridge. Most of my classes are at night and I don't really want to ride home from the station at 7-8 PM, let alone leave my Jamis hybrid there all day.
When it's 40 I am wearing tights over shorts, a sleeveless base layer, a medium or light weight wool or fleece jersey and a wind jacket. Oh yes, and a head cover (light fleece), full fingered gloves, wool socks, and booties. As it gets to 45 I lighten up on the jersey thickness.
I don't like riding in the heat even more than the cold! really 55-72 is my favorite temperature. It is going to be in the 90's this weekend and I am already dreading it. I'll be out early this weekend.
I don't know how you ride in AZ. I used to walk at 5 AM in Tempe and even that was pushing it. And I was young then!