If you really want to swim I would not pick January. Some people will swim at this time, the pools are heated, but the air temp will probably be chilly, too chilly for us but then we are really southerners. The crowds will be heavier, though, in March and April because school spring breaks are spread out during those months. The week before and the week after Easter will be the worst, and next year Easter will be the end of March. It really depends on what you want to do and how well you handle crowds. Some people freak out if they have to wait in any line at all, but we just feel like that is Disney, we always go when school is out. We don't do commando and whatever we miss we will just see next trip. Hope this helps...Lacee