Zero here. New years eve was minus 15. That was really cold for a dress shirt and leather jacket. The air was so still, you could actually warm up a little by standing perfectly still. Once the air next to your skin and clothes warmed up a little, you felt warmer. I amused myself for a few minutes standing perfectly still with my fingers curled up inside the cuff of my leather jacket and then extending them outside the cuff and counting the seconds before fingertips go numb.