Winter can be boring if you let it be boring. I agree that you should stay in during an ice storm or blizzard or below freezing temperatures.
But just being cold you can still go outside and get some exercise, go sledding if there is snow, go ice skating, just be careful and not go out on icy ponds that you don't know how thick they are or the ice could break and you could die.
Have a snowball fight etc. There's lots to do in the winter if you just think about them and get out there and do them.