In winter, it is often warmer in San Francisco than in Sacramento, 150 km inland. In summer, it is nearly always hotter in Sacramento. Explain how the bodies of water surrounding San Francisco moderate its extreme temperatures.

The water body around San Francisco serve as a heat sink which absorbs excessive heat during the day and in turn supply San Francisco cool sea breeze to maintain the temperature by a process known as convection whereby the hot air of the land is replaced with cool sea breeze. This phenomenon makes it possible for San Francisco to maintain a fairly stable temperature range.