I agree with CKone. :icon_razz: We were there this Sept and last February. The biggest difference that I remember (a significant limitation mind you) is that the sun goes down earlier and the pool water was cooler, so if you were getting out in the shade it was chilly. Once we were dried off and dressed for nighttime we were always fine in summery/sexy clothes. I'm sure it does occasionally get cool enough that you'd want long sleeves of some sort for dinner, but we didn't experience that. Summary: plan on wearing short sleeves, sleeveless, skimpy, skimpier, and so on, but maybe throw in a jacket or sweater just in case.
We used to go in January but the weather was volatile so we now go at the end of February. By that time, we are really sick of Midwest weather and need sunshine. By mid to end February, the weather is usually mid 80's, no humidity and gorgeous. I have not had the need for a light sweater or jacket in the evenings in February as I did in January. I remember being in the pool quite a bit last year. To us, the last part of February is about perfect. Cheers!