I can only share our experiences - we have cruised May, February, and March. In May, the weather was fabulous,
Castaway Cay was paradise, and the water was bath water. In February, the water didn't permit us to get to Castaway Cay. In March, we got to Castaway Cay and it was warm enough but the water was brrrrrrr cold and only the brave souls (read: kids and their loving but cold parents) got in the water. So all of that being said, I'm very pleased with the choice of May! Thanks Round Table team!!!