For the most part we have been to Walt Disney over July 4th than any other time! It is hot and crowded but apparently we don't mind! LOL! We keep going back! LOL! So my comments are based against this week.
We went to Universal last September (2013)for labor Day weekend and to Disney the following week.
I am a summer person, I live in the south, I grew up with no air conditioner in the house or car. But At Universal the heat, humidity was bad. I thought it was worse than over July 4th. I tried to stand in my husbands shade while in line! LOL! It was Hot! Seems like Universal just didn't have anywhere to be out of the heat.
When we arrived at Disney we handled the heat better for whatever reason. I don't know if the weather was better or it is because Disney had better places to be out of the heat. The crowd level for that following week after labor Day was great! Kids were back in school I guess. Disney was decorated in Halloween decorations and the Halloween Party started that week at MK. They started it early last yr apparently. Theme park hrs change in the fall closing parks sooner. It was good weather for the pool or water parks. No Jackets of course were ever needed. LOL!
We went a couple of yrs ago about the 3rd week in October. The crowd level was better of course than in July but September may have still been lower. Really not sure.
It was cooler weather and I needed a mixture of clothes, Anything from a Jacket or sweatshirt in the morning & evenings to short sleeve shirts & shorts by afternoon. I enjoyed the afternoons but didn't the cool mornings. But I am a person that would rather be hot any day of the week than cold, except that one day at Universal! LOL! I like to breathe! LOL! I don't know if this is the usual weather for Florida but I do not remember it raining one day that week in Oct!
But the pool was very cold! LOL! Other families with children were complaining to the life guards about the pool and that it was supposed to be heated. The lifeguard said it was cold but Disney did not turn on the heaters until November.
I have never been to Disney in May or November. But I think I could go any month and have a good time at Disney! I would love to go one time and see the Christmas decorations even if I did have to wear a coat and was cold! LOL! Hope you have a magical week whenever you go!