L.A. Fire-Fueling Winds Slow Down, Offering a Short Reprieve. What Are the Santa Ana Winds, and Why Do They Fan the Flames?

The fires around Los Angeles continue to rage on, after scorching some 40,000 acres of drought-parched land. The Palisades and Eaton fires have together killed at least 27 people and displaced tens of thousands more, making them some of the deadliest fires in California history.

In recent days, however, the region’s powerful Santa Ana winds—which have been fanning the flames—have begun to slow down. This lull has offered firefighters a reprieve and a key opportunity to make progress against the blazes, but forecasts suggest the Santa Ana will return next week. What are these gusts, and how have they become so strong?

“This is not a typical Santa Ana, but this is the time of year when you expect it,” Daniel Swain, a climate scientist at the University of California Los Angeles, said in a livestream, per Vox’s Umair Irfan.

The Santa Ana winds are a seasonal occurrence in Southern California. They push inland air from the desert over California’s mountains, making it grow warmer and drier as it reaches the coast. As the winds funnel through canyons and valleys toward L.A., they gather speed.

This year, ocean heat has likely made the winds even stronger. Warming oceans can cause the jet stream—a narrow, high-altitude current of fast-moving air that influences weather across the continent—to move off course. This can create a patchwork of high- and low-pressure systems over California that supercharge the Santa Ana winds. Last week, gusts were as high as 100 miles per hour.

“These ocean heat waves are becoming stronger and larger because of heat trapped by increased human-generated greenhouse gases, so these persistent and unusual weather patterns will probably become more common,” says Jennifer Francis, a senior scientist at the Woodwell Climate Research Center, to Bloomberg’s Lauren Rosenthal and Brian K Sullivan.

The Santa Ana winds are a natural part of the state’s weather and have exacerbated wildfires before—but when these gusts are paired with abnormally dry conditions fueled by climate change, it can make them especially destructive.

“These winds come every year,” Crystal Kolden, a fire scientist at the University of California, Merced, told National Geographic’s Alejandra Borunda in 2020. “The question is: Are they going to come when it’s wet or when it’s dry?”

For 2025, it’s the latter: Winter usually brings rainfall to Southern California, but that hasn’t been the case this year. “We haven’t had any substantial rain for hundreds of days,” says Max Moritz, a wildfire specialist at the University of California, Santa Barbara, to NBC News’ Denise Chow.

The region’s current dry spell follows two wet winters, which led to exceptional vegetation growth, as Swain tells Elizabeth Kolbert at Yale Environment 360. Then, the rain stopped, in what Swain has called “hydroclimate whiplash,” or a sudden shift between wet and dry weather. After months without rain, all that vegetation has become fuel for fire. The winds then contributed to the fires’ fast-moving and erratic spread, helping them blaze through a heavily populated area, leading to a lot of destruction.

While the region is currently getting a break from the Santa Ana, meteorologists expect the winds to pick back up early next week.

“Next week is a concern,” wrote the National Weather Service Los Angeles in a post on X on Wednesday. “While confident that we will NOT see a repeat of last week, dangerous fire weather conditions are expected.”

As of today, the Eaton fire has reached 65 percent containment and the Palisades fire is 31 percent contained, according to Cal Fire.

The long-term effects of the wildfires remain to be seen. Once the health impacts from exposure to smoke, which contains pollutants and dangerous fine particles, are fully understood, the eventual death toll is likely to rise dramatically, writes Jeff Masters for Yale Climate Connections.

Sara Hashemi | READ MORE

Sara Hashemi is a science writer and fact-checker currently based in New York City. Her work has appeared in Sierra, The Body, Maisonneuve magazine and more.