For the season and weather, September is really nice. I also like July, and December as well! I'm avoiding naming any spring months because allergies :c
As a guy who lives close to the Maritime (known for its fluctuating temperatures and countless amount of snow during winter) and no longer studying at schools, pretty much anytime between mid-May and mid-October is good for me. Though, one month that stands out among the crowd is September.
This one still have its comfortable weather going on, but it usually never goes beyond 25?C. There's still quite a lot of going on in terms of video games, activities and whatnot, for a month that's at the tail-end of summer.
November and December are the top runners for me. November because (typically, not so much a guarantee in recent years, sadly) the heat is finally gone and it's the furthest month from the return of the miserable hot weather. December because it is the most likely month to actually have wintry weather.
I love the smell of dead leaves and watching them change color, and watching horror movies all month long. Except I watch horror movies nonstop year-round. I also love dressing up, going trick-or-treating, and running around singing "This Is Halloween" with my little sister.
I've always loved December because of all the Christmas festivities. It's probably the time of the year when I feel the happiest. I also like June since it's the start of a summer holiday and summers have always given nice memories.