Hi,
We always go the first week of Aug. We will be at the ASMo this year. It is usually HOT!! It is usually in the 90's with at least a shower everyday. Remember to bring the rain coats and the sunscreen. We are from Ohio and a few years ago it was cooler in Florida when we were there than it was at home. We were having a heat wave. We like going in the summer because the parks are usually open later.
Take your time and drink lots of water. We always pack the little battery operated fans that hang around your neck. The really help.
Have a great trip.