I was in WDW from June 18-26 and again from Aug 5-9. I was there on Thanksgiving Day and stayed until the following Wednesday. Here are my thoughts...T-Day is a zoo in MK, we all know that. But, at least it is not blistering hot and drenchingly humid!! In June, and then again in August, I found the crowds to be high. Add that to the heat/humididty and well....it was not a good combination. Yes, there are people that can only go during the summer. But, if you can get there in late August then you may be better off. The kids are back in school in a lot of areas and that cuts down on the number of people in the parks at least during the week. When we went in '03 we were there for the 15-21 of August and it was hot but the crowds were okay..higher than usual due to the FairyTale pkg. Then last year we went Aug 13-22...it should have been okay but Hurricane Charley came and the schools shut down..so more Floridian kids in the parks. But, all told...late August is the best time to go crowd-wise.