December in Phoenix

It's Decemberrrrrrrr. Bring out your warm and thick jackets. So they say

But in Phoenix? Nope. A light sweater will do at nights. During the days, a shirt is all one wears.

It will get a little cooler though in January. So I heard. I will be ready.

Elsewhere as in Yosemite, California (below), a thick jacket is a must.