been there in January when it's low to mid 80's, minimal wind and absolutely lovey. One trip we did a "back to back" - well we had 3 days inbetween sailings ... the first day in Nassau was that lovely weather, 7 days later, the temps were still near 80, but it was overcast and windy and after 7 hours at the Atlantis water park we were getting chilly (but yea, we were still in the water - so it wasn't that bad!!).
Have also been there with Wind, Rain (heavy) and low 70's and totally miserable. We had a 12 hours to kill after getting off the ship and Orlando was in the low 50's and no coats for us so it was a cold day in Disney Springs!!
Weather Happens!! and Disney still cannot control it! (
Disneyland New Years Eve Fireworks got cancelled)
I would watch the Orlando / Port Canaveral weather in the days leading up to your cruise along with what the weather is doing in Nassau.
And remember, there will be Air Conditioning on ALL of the Time onboard - so you might need warmer than expected clothing for INSIDE the ship!! Especially Dinners and Shows - if they don't keep the temps down before / early on, with all of those hot bodies (by hot I mean 98.2 degrees

) there's no catching up and cooling the room down.