I vote August!!!! I love going during this month. Yeah, sometimes its hot, but the rain comes (usually quickly) and its then kind of cooler. August of 2002 we went, and it was really hot. We looked forward to that 15-30 min rain storms, which cooled us all off and then it was back to business. Last year however (August 2003) we were there during the Hurricane further South and Orlando was perfect. I'm talking mid- 70's from the Sunday - Thursday. No rain, and it was warm enough to get in the pools because of the humidity. Friday - Sunday was warmer in the upper to mid 90's. This August 8-15 we are returning and I'm hoping for the cooler weather, but it not I'll find a wet ride to cool me off.
The crowds brings excitement to me. I went to Disney/US in September 2001 (a few weeks after 9-11) and it was almost boring. The parks were almost empty. We couldn't hardly find the characters, and everything seemed so "dead". Now I realize that we were all going thru a tough time, but I thought Disney would be a great diversion. NOT!!!!!!