Be mindful of weather. That's a very rain-prone time for some places, and if they get the really bad stuff (floods, typhoons, etc.) then that's the most likely time of year. For a place like Thailand it's an excellent time to hunt for deals, but they're deals for a reason. Some years you get away with it or just get rained on and watch your bus try to go through a foot and a half of water, but other years you get the more serious stuff that makes the news.