As a result of hydrogen bonding among water molecules, it takes a relatively large heat loss or gain for each 1 C change in temperature. Hydrogen bonds must absorb heat to break, and they release heat when they form. A large body of water can act as a heat sink - absorbing heat from sunlight during the day and summer and releasing heat during the night and winter as the water gradually cools.
Coastal areas have milder climates than inland.
The marine environment has a relatively stable temperature. Transformation from liquid to a gas. Molecules with enough kinetic energy to overcome the mutual attraction of molecules in a liquid, can escape into the air. Quantity of heat a liquid must absorb for 1 g to be converted to the gaseous state. For water molecules to evaporate, hydrogen bonds must be broken which requires heat energy.