Odds are you are going to get very nice weather in October. It's our favorite time of the year to go. However, cold fronts can sometimes dip into the 60's in October at night. Because Orlando is so far inland, the ocean breezes and currents don't help keep temps warm, so it does tend to cool rapidly after dusk on clear nights. Now 60's may be bikini weather to some Canada, but to us it is cool and requires some additional layering. I remember in Oct '03 that coming out of the warm pool was rather chilly, even though it was in the mid to upper 70's. Last two years has been extremely warm, even in the "cold" months.