We have gone in May several times and have always found it to be the perfect time. The weather is perfect, warm and sunny but not too humid, and the crowds are not bad at all. This past May we were there for 10 days and it was very, very, very, crowded. I believe that is due to the 4/3 promotion that they have been offering. Also, it rained for 9 out of the 10 days.....POURED! I would recommend early May, first or second week and you should be fine. Hopefully the weather will be fine too! Historically, it is not a rainy time for central Florida!