we have been in May and October.
It is far less humid in May, and rains much less than October. Usually in a 2 week stay we have had two afternoons of bad weather and clear blue sky the rest of the time.
It is hotter I think than in October, but easier to deal with as it is a dry and less humid heat.
I have been all through May, and it does get progressively hotter at the end of May than at the beginning, but you know Florida weather.. its very unpredictable!!!
October when we have been there has often been quite cloudy and rainy.. with sunny days in between.
May is my all time favorite time to go. Sadly as my son has now started school we can no longer go in May, but I love it then!!