The climate is generally sunny, dry and cool, although evenings can be damp due to the ocean breeze. Prevailing westerly and southwesterly winds off the Pacific Ocean help maintain pleasant, smog-free weather year round with temperatures ranging mostly from 65° to 80° Fahrenheit. The mean annual humidity is 64.7%. In the morning and evening, there are strong breezes, about 15 mph. In the summer, temperatures rarely exceed 85 degrees. In the winter, temperatures rarely fall below 40 degrees, even on clear nights. Annual rainfall is less than 12 inches, with a majority of the rain falling between December and March. Frost occurs only rarely on the coldest winter nights. Ocean temperatures average 55 to 65 degrees.
Solar energy can also be used for making potable, brackish or saline water. Without using electricity or chemicals, waste water can be treated. Creating salt from sea water is also one of the oldest uses of solar energy.