Helping drive the wildfires in the US city of Los Angeles are the so-called Santa Ana winds, a weather phenomenon known to dry out "the hills and the nerves to flash point."For Joan Didion, they blew "sandstorms out along Route 66,

The Santa Ana winds are dry, powerful winds that blow down the mountains toward the Southern California coast. The region sees about 10 Santa Ana wind events a year on average, typically occurring from fall into January. When conditions are dry, as they are right now, these winds can become a severe fire hazard.

The devastating fires that have killed at least five people and forced the evacuations of tens of thousands of residents across the Los Angeles region are driven by Santa Ana winds that blow from the deserts of interior California and Nevada out to the Pacific Ocean.