Watch mid January.. It will get a bit crowded ( by January standards) over Martin Luther King weekend. Other than that... January is wonderful and not crowded. We have been there the past 8 January's and have had quite a few hot, sunny days where you could enjoy the water parks or the pool. I think its a great time to visit.. low crowds.. nice warm weather ( occassionally you will get a cold nights/mornings but for the most part, its been great weather for us). Its really nice to go to Disney, and get to see and do a lot because of low crowds. I also like that its not so hot, that you are dripping sweat (like our September trip this year) I cant wait to get back there this coming January!!