I went in September in 2000, the only thing I remember is how I never knew Florida could be so hot in the end of September lol !! I took my kids in 2010 in December. We honestly love December but like I said we are usually there the 15-21. This is the closest to Christmas we have ever been. I am hoping people wait until the 23rd to come since Christmas is on the weekend!We have never went during this time...may and September were our last trips...so I am preparing for the worst with crowds and hoping for the best! Yeah our school is wonderful about them missing...we create a "journal" during the trip and thru show it to their class and talk about what they learned (hall of presidents and Epcot world showcase come in handy here!).