Orlando Weather In September

September Weather In Orlando is just slightly cooler than August, and the chance of rain drops slightly as well. Still, of you were betting, bet that your September vacation in Orlando will include hot, humid weather, and some thunderstorms. The September Weather In Orlando will not ruin your vacation, but it's something to plan for, you should either bring a rain poncho or purchase one at the theme parks. Umbrellas are less effective because of the wind that usually accompanies the rainstorms.