The specific heat of water is higher than the land. Means it cools slowly and heats up also slower than land. The wind pattern of places near large water bodies or in fact sea is either from land to sea or from sea to lan. In the daytime the land gets heated up faster than water, so the pressure over land is lesser than over sea and the wind flows from sea to land bringing the temperature of the atmosphere over land down. In the night reverse happens. that is why the temperature of places near sea is generally constant.