Weather Words: Diablo Winds

If the Santa Ana winds are famous for fanning flames in Southern California, their lesser-known but equally dangerous cousin, the Diablo winds, wreak havoc in the north. These hot, dry, and powerful downslope winds sweep across Northern California, especially in the fall, creating extreme wildfire danger. They form when high pressure over the Great Basin forces air westward toward the lower-pressure coastal regions. As the air descends over the Sierra Nevada and Coast Ranges, it compresses, heats up, and dries out, creating prime conditions for wildfires.

These winds got their name from Mount Diablo, a prominent peak in the San Francisco Bay Area. Early weather observers and firefighters noticed that these strong, fire-fueling winds often funneled through the region. The name “Diablo,” meaning “devil” in Spanish, reflects their destructive nature, capable of rapidly spreading flames and making firefighting efforts incredibly difficult.

Similar to the Santa Ana winds in Southern California, Diablo winds can reach speeds of over 70 mph. Combined with dangerously low humidity and dried out vegetation, they can turn a typical beautiful California day into a raging inferno in a matter of minutes. They have played a role in some of California’s most devastating wildfires, including the Tubbs Fire in 2017 and the Kincade Fire in 2019.

While Diablo winds are a natural weather pattern, climate change is intensifying wildfire risks by drying out vegetation and extending fire seasons. As a result, these winds remain a major concern for California’s wildfire preparedness and response strategies.

Jennifer Gray is a weather and climate writer for weather.com. She has been covering some of the world's biggest weather and climate stories for the last two decades.