ParanoidAnnie we were in Orlando last year for 2 weeks from 22nd of August. It was our first trip- 2 adults and 2 boys, and I had been told lots of horror stories about it being 'far too hot and wet to go in August' and was getting quite worried about it!
However, although the heat and humidity took a day to adjust to, and we were there when there was a tropical storm so rain for one whole day at least, we had an amazing time!
My ds2 (aged 13 now) talks about our trip every day still! I would just advise you to be prepared- buy ponchos, plan your days for wet or dry days so you don't waste time thinking about what you can do (we went to DisneyQuest on the wettest day, got there early and they let us in) use lots of suncream and drink lots of water on hot days and try not to worry about it.
I'm very
of you - would love, love, love to go again and would definitely go at the end of August again- the parks are relatively quiet and if you get there for park opening and go straight to your preferred rides you will not queue for long. The longest we waited for a ride was about 20 minutes- don't forget to use your fastpasses. Even at Universal - we got there for opening and went straight to Harry Potter and queued for 10 - 15 minutes.
Hope you have a fabulous time
.