We have gone down for the past 5 years in the last week of August. That is the only time that we can go that is a non-peak time of year for Disney, and also that my kids are out of school. The kids in Florida go back to school during the first week of August.
The crowds are significantly lighter in the last week of August compared with July. So if you have to decide between July and August, I would go with the last week of Aug.
Now as far as the heat goes, I am not a big fan of heat and humidity either. I can say that you will probably find it almost unbearable most of time, like I did. Last August we got up early and went to the MK to do the Space Mountain Marathon (we eneded up being the first to go also!!!). Anyways, it was about 8am, and we were standing in the sun just inside of the turnstiles waiting for them to let us in, and I could not believe how hot it was. This was at 8am.
Later that night, we got to the MK to watch Spectromagic. We got a seat on the curb around the hub on Main Street around 7pm and waited till the parade started at 9pm. It had thunderstormed earlier in the afternoon (as it does everyday in the Summer in Florida), and this made it so humid that we could barely breath. It felt hotter at 8pm then it did at 3pm.
Everytime we watch the video, I just think back to how hot it was.
Some people are going to say that it isn't too bad. DON'T BELIVE THEM!!!
This is coming from someone who runs 3-4 miles everyday and is in good shape. I just don't like heat and humidity.
Every year after we the trip ends, I swear that I will never go back again in August. I told my wife it's kind of like childbirth I guess. Right after you swear that you will never do it again, then after some time passes, you forget the pain and suffering.
Oh well, other than the heat, you should have a great time
