What part of California gets most rain?

California's average annual rainfall varies immensely, from around 1,800 millimetres (70 inches) in the North Coast at Crescent City to less than 50 millimetres (2 inches) in Death Valley and the Imperial Valley.

Typically California has a wet season which ranges in length from four months (December to March) in the south at San Diego to around eight months (October to May) at Crescent City. The rest of the year is a dry season dominated by the strong North Pacific High, which suppresses moisture during the summer except for occasional cyclones affecting the southeastern deserts.

During the wet season the Aleutian Low forces moist air onto the coast of California, giving heavy rain generally in the north and, if the Low is further south, even in San Diego.

Variations in the position of the Aleutian Low and the stength of anticyclones can cause large variations in rainfall: at Los Angeles rainfall can vary from 980 millimetres (38 inches) in 1883/1884 to 80 millimetres (3.2 inches) in 2006/2007. Heavy rain in California frequently causes disastrous and large floods, especially in the erosion-prone North Coast where major rivers can reach flows as high as that of the Yangtze (largest river flowing into the Pacific in the world).