What are fun things for us to do?

For the time being it's winter. Now during the summer i know a few things we could do. But i can't think of anything. We're both 16 and we have been together for almost 10 months. I'm not sure what we could do during the winter months until it starts to get warm.. We always hang out at my house and watch movies. Or we go to his house and just hang around. Or we just go to the movies when we get tired of doing any of that. We're just running out of things to talk about. Any advice as to stuff we could do together while it's cold.?