Well, what else is there to do in the winter, really? Oh wait, hockey. But still!
Skiing, snowboard, snowsurfing, snowskating, skating, (for adults) cross country skiing, polar bear club (also mainly for adults) snow soccer, snow football (yes, its an actual game), snowshoeing, bobsledding (if you know a good course), sledding, ice fishing, some kinds of hunting, (for the kids and the grossly immature or parents of kids) snowforts and snowball fights), I could go on but I won't.