A typical winter day is below freezing but above 0. Snow will fall and usually melts away a few times before sticking around until spring. Lows in an average year will have a few nights that drop below -10, but won't hit -20.

That said, there's a huge difference between the average and the extremes we sometimes get. Any given day in winter can range from about 50 to -50. I've had multiple apartments where frost forming on the walls was a problem. We might get absolutely buried in snow, or we might have almost no snow all winter and then get a blizzard in May. Last year the USDA updated plant hardiness maps and our area went up a level, then a month later we had a massive storm and deep freeze that killed a lot of trees.