we have been in May several times and September 3 times in recent years...expect it to be hot & chance of rain about every day. We've been there in May when it's running 88-94 F every day and very humid...pouring for an hour every day. We've also been when it's 80-85 and dry -- drought conditions. So yes, it will probably be hot, and very well may rain. But May is not near as hot & humid as September I don't think.