All water bodies like seas and lakes act as storage heaters and ten to equalize the climate.
During the day, as compared to land, the water bodies take more time to get heated as well as to cool down.
During night, water releases the heat slowly, keeping the air mild until the following morning. So, sea coasts do not experience extreme variations in temperature, but always have mild climate.
Below Climate info from Wikipedia (Read More):-
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and numerous other meteorological elements in a given region over long periods of time. Climate can be contrasted to weather, which is the present condition of these same elements over periods up to two weeks.
The climate of a location is affected by its latitude, terrain, altitude, ice or snow cover, as well as nearby water bodies and their currents. Climates can be classified according to the average and typical ranges of different variables, most commonly temperature and rainfall. The most commonly used classification scheme is the one originally developed by Wladimir Köppen. The Thornthwaite system,[1] in use since 1948, incorporates evapotranspiration in addition to temperature and precipitation information and is used in studying animal species diversity and potential impacts of climate changes. The Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses defining the climate for certain areas.
http://en.wikipedia.org/wiki/Climate
