We go every August. It's not that bad. Maybe it's just us but the heat and the crowds don't bother us. We love it. We've meet so many interesting people waiting in lines. The best thing is that it stays open so late. It seems like you can go on more rides from 8pm-10pm than you could all day. So that's when we go on rides like Space Mt, Splash Mt, Pooh, Buzz Light Year. It is really hot in August and it helps to watch a show (like lion king) in the middle of the day, so you can sit in a/c. If possible the best thing to do is go back to the hotel for a swim or even a nap. We say naps are like having two days in one, and in August since the hours are till 10 you have plenty of time for a nap. Hope this helps! Don't worry Disney is the best and as long as you feel that Disney magic you won't care about the sun or the lines