Since water acts as a heat sponge, if you live near a coast or a large water body, the temperatures on the shoreline are much more temperate than 50 miles inland. The Sun heats up the ground quicker than water, and the temperature of the ground changes by 5° for every degree that the water does. On the other hand, during winter, the ground gets cold and freezes much faster than a water body does. So the coastal winters are generally milder than inland.