“It takes awhile, in the fall, for the oceans in the northem hemisphere to cool. So by winter the oceans are cold and the temps keep going down.”
Even though days are getting longer, there is still a net loss of heat resulting in lower temperatures.
The heat capacity of the ocean is much greater than that of the atmosphere or the land. As a result, the ocean slowly warms in the summer, keeping air cool, and it slowly cools in winter, keeping the air warm. Oceans moderate temperatures along the coast, causing summer to be less hot and winters less cold than in the interior. The surface temperature of the world’s oceans varies mainly with latitude, with the warmest waters generally near the equator and the coldest waters in the Arctic and Antarctic regions.