Pools are heated, so their temp remains consistent (82 degrees, I think). But it's the air temp that will get you. We were at WDW the week before Disneyfamilyoffour, and temps were in the mid to upper 80's every day, so swimming was very enjoyable. The next week, temps were in the 60's, too chilly for most people to spend much time poolside. So you never know. Best bet is to check the Orlando weather forecast just before you leave, so you'll know what the temperature trends will be for your week.