It is winter in puerto rico. compare the air temperatures beachgoers feel near the water
to beachgoers who are still near their hotel room 25 miles away?

look at pg 4 on the attached file.

Large amounts of water do have a big impact on the weather: indeed, it takes less energy to warm/cool land than water.
Therefore, places near large amounts of water tend to have smaller differences in temperature between summer and winter than places far from waters.

Hence, during winter in Puerto Rico, alongside the coast, the temperature will be higher than in the innermost parts of the island.