There's something about August ending that gets me thinking about Autumn. I guess that's normal. Perhaps it's the rain, or the cool wind I feel in the late afternoons, or the fact that it's getting darker earlier here in the U.S. I think it's also the knowledge that once October 1st arrives, the space between the beginning of my favorite month and December will fly by. Whatever the reason, with a mixture of expectation and melancholy I look to the coming seasonal change.
Do you "play" in the different seasons as GM? Do the seasons change in your campaign world?
I've rarely had a campaign run long enough to track the change of several seasons, and of course seasons might vary in a fantasy world (winter in Athas, anyone?). But I definitely find running temperate zone adventuring a bit boring, and I think it wrong that a party might have travel way up north just to see a little snow. (Perhaps that's my real-life location speaking to me—living in the northeast USA, I typically see temperatures ranging from 20 to 100 degrees F, and snow is hardly uncommon during the span from December through March.) I rather like the weather-related variety, myself.
About a year ago I began a new 4e campaign (you can read Ken's wonderful synopsis starting here) and I vowed to make it a little different. The initial session, I steered the party toward the beach and sand, and had them playing in the surf with huge crabs, all in an attempt to get away from the typical wooded hills. The attempt was semi-successful, but as the campaign continues (hopefully for a while) the group will voyage across the sea, visit the desert and a Cairo-style city, and explore southern jungles.
Sometimes a little seasonal change can be enough to make that standard campaign just a bit different. So the next time your group sets out looking for that long-lost tomb or crumbling keep, have them encounter some fresh-fallen snow, some driving hail, or perhaps a thick morning fog (all preferably combined with a dangerous encounter)—both you and your group may find it a refreshing change of pace.