I do remember a 3rd of January in Fort Lauderdale prior to a cruise where the flower beds were all covered up in plastic and the orange groves had the smug pots going to ward off frost. We didn't swim in Key West but further south we did. It was colder in Florida that here in the Lowermainland of BC. Had to go to a thrift shop to buy an heavy sweat shirt.
But in the Caribbean was just fine.!!