It comes on quickly, disappears slowly, just when everyone is looking forward to more warm days of spring and summer, Southern Californians have to grab their sweaters.
Everybody has heard of the Gold Rush, when sleepy, remote California got a flood of gold settlers, in a land they all knew very little about.
But, Edwin Bryant who wrote a book about his first visits to California in 1846, warned all the wagon travelers to the new territory that when they finally staggered into San Francisco in the late summer, they should bring their winter woolies.