Seasonal hobbies: What are your summer/winter hobbies?

What are some hobbies you do specifically when during this time of year (whether it's your summer or winter)? And what do you do in the opposite season?

When I'm home, summer is when I do some light woodworking projects. Currently I need to finish a shadowbox that will be illuminated with LED strip lights. I also have to finish a bat house that needs a little more work before I can do a final assembly and install it on a post.

I don't really have any specific hobbies for the winter, besides crushing my music backlog while reading, so I'm interested to see what other people do.

I was intending on posting this before the season actually started, but here we are. :)