My first winter in Arizona. It's not that cold than I expected. The winter in Arizona does not get as cold as in Tokyo. It's more like winter in Okinawa. However, it is cold in the morning and evening due to the desert climate.
Jackets or sweaters is fine. I've never seen people wearing a long coat so far.
There are quite a few people wearing T-shirts during the day. ( I can't do it it's too chilly. )