Hi Jaime!
Welcome to the Disney Parks Moms Panel! Florida is known as The Sunshine State, and Walt Disney World Resort is The Most Magical Place on Earth, so it's only fitting that Mickey and his pals are able to swim any time of the yEAR.
I'm very happy to answer with an enthusiastic 'Yes!' that both
Disney's Typhoon Lagoon Water Park and
Disney's Blizzard Beach Water Park, as well as the main pools at all
Disney Resort Hotels are indeed heated to a splendid 81 degrees year-round. Do note that Disney's Water Parks take advantage of the fall and winter seasons to close one water park at a time for a deep cleaning and refurbishment period. While Disney's Blizzard Beach Water Park is currently closed until January 5, Disney's Typhoon Lagoon is open daily from 10:00 A.M. until 5:00 P.M. Then, starting on January 6 and lasting until mid-March, Typhoon Lagoon will close for its annual refurbishment, at which time Blizzard Beach will open for some winter water fun. Also note that water parks and pools do close should the outside weather reach Arendelle 'Frozen' conditions.
Disney Resort Hotel guests can get to both Disney Water Parks via Disney's Resort Buses, however you most likely will have to make a *transfer stop at Disney Springs or a Disney Theme Park first, so be sure to pack bus-worthy coverups. (*There will be well marked signage at the Disney Resort Hotel Bus Stops listing that days transfer route.)
And if you plan to spend time at your Disney Resort Hotel pools, there are plenty of extra towels poolside, so you won't need to pack your own or bring the ones from your resort room. Complimentary life jackets of all sizes are also provided.
We'll See You Real Soon, Jaime!
~Kristen