My 3 favorite activities to do in winter are:

Basketball
Playing in the Snow
Having hot foods

Basketball you can play anywhere as long as you have a basket and some ground preferably concrete. I really fun and you can get really excited. Many people want to make it to the NBA but i don't really care for that i just like playing. You can see most games or highlights on ESPN.

I like having snow ball fights. They are fun in my opinion.There's nothing really much more to say but they are fun making the fort and making the snowballs.

I also like having hot foods to make me warmer. Like from my Keurig coffee machine that i make hot chocolate with. More food is hot pockets.