This is a think jacket, something you can even wear in good summer weather, so don't count on it as a winter jacket!
I took the advice of most customers and bought a size up...I usually wear 1X but bought 2X.....NOT ENOUGH! this was more like Large. I though I would wear it and keep it unzipped....but the arms were too tight for me. Too bad because I really liked the style and it was a well made jacket.