My husband and I went Feb 11-18 of this year and only one of the two water parks were open. I think their annual refurbishment is in Feb.
As far as weather, we were coming from SNOW to Florida weather, and we still decided against it...it ended up being a little cooler than forecasted, about 70-75 on average which is perfect for walking around the parks but in the morning it was cold! A couple of our afternoons would have been great water park days as it did end up getting pretty warm, but the weather is so unpredictable.
I would just play it by ear if you can.