Many factors here, where to and from, is it a direct flight or do you have to connect with a second flight? If you are going to Fla. or the Gulf Coast, Sept can be prime storm season. Weather of course is always the prime concern no matter when or where you are traveling, but this day and age I have less faith in the airlines than ever before, they seem to cancel more flights than I can remember. We used to fly the same day but got burned once when we got stuck in Chicago, now we always fly a day early. In any case I hope you got travel insurance that would help ease the pain some in the worse case scenario if something should happen beyond your control. Hope everything works out well and have a great cruise.