When hurricane-force winds whipped through Los Angeles County in early January 2025, the hills had ample fuels available to feed a wildland fire.
When hurricane-force winds whipped through Los Angeles County in early January 2025, the hills had ample fuels available to feed a wildland fire. Back-to-back wet years in California led to grasses and chaparral accumulating in the mountains and foothills. Then, warm, dry weather in Los Angeles during the last eight months of 2024 left the vegetation primed to burn.
On January 7, blazes spread quickly in the hills of Pacific Palisades and Eaton Canyon. Santa Ana winds pushed the fires down hills and into neighborhoods, and the two fires eventually covered 37,000 acres (150 square kilometers). Most of the fire spread in the first day after ignition, a characteristic of “fast fires.” These destructive events are usually propelled by strong winds and burn in the autumn or winter when fuels are exceptionally dry.
Researchers at the University of California, Los Angeles (UCLA) noted that several factors contributed to the severity of the fires, including a buildup of vegetation between 2022 and into 2024, followed by very warm and dry conditions in summer 2024. The rapid swing from wet to dry—dubbed “hydroclimate whiplash”—can amplify the risk of wildland fires and has become more common in the 21st century.
Read More: Stanford University
Stanford Assistant Professor William Tarpeh and PhD student Samantha Bunke in the Tarpeh lab. (Photo Credit: Bill Rivard / Precourt Institute for Energy)
