BeBelize, I doubt that May is the hottest month. Have you been there in August ?
I read this in a couple of different articles on Belize weather. Perhaps they had their facts incorrect. I was here on vacation in August 2010 and moved here in August 2011, and yes, they were also hot times. I honestly couldn't tell much difference between May and August, but that is just what I read. Either way, both months are pretty darn hot for anyone who is not acclimated.