I was wondering the same thing... We live in CT and go to WDW several times a year. In fact we are on our way home from this last trip.

We are used to heat and humidity so that isn't as important as crowds. My kids, ages 5 and 8 next summer, have never been to DL so I am looking for times of smaller crowds. We can never predict how many snow days we will have (last school year we had so many that they went until the very end of June). The last week of June was our plan but I'd hate to run into July 4th weekend.
I was now thinking the 3rd week of August which will be my 8 year olds birthday. Do crowds start dropping off about that time? We will only have 4 or 5 days there and they like to do rides more than once. Thank you! DH and I have only been to DL once and that was 11 years ago!