Both of our cruises have been in January. The first was the 3 night and the second was the 4 night. It seemed as though the temperature may have been just a wee bit warmer on our first cruise, as was the water temp as well. It was still warm enough to wear shorts on the second, but the water was definitely a lot cooler. Even on the ships, if you weren't in the direct sunlight while in the pools, it was chilly there as well. At CC, we did the Stingray excursion, and the water was definitely cool there. In fact, after we finished our excursion, we didn't get back in the water at all. But I do love cruising in January, and if we ever go again, it will most likely again be in January.