On a warm summer morning, two fire officials navigate an SUV along a narrow road that switchbacks high into the hills above the town of Fairfax, California, where thickets of trees conceal hundreds of homes. When the road dead-ends, they head back down through the same hairpin turns, pointing out where a wildfire would roar into the path of fleeing vehicles.
“Most communities were not designed to accommodate every resident evacuating simultaneously,” said Dan Mahoney, chief of the Ross Valley Fire Department, which serves the town of 7,500 in Marin County. “In a lot of areas, there’s only one way in and out.”
With climate-exacerbated heat waves triggering blazes across the U.S. and around the world this summer, evacuation is fast becoming an existential challenge. Firestorms now ignite without warning as temperatures soar, increasingly spreading at lightning speed into cities like Los Angeles that border wildlands. Mounting death tolls in the U.S., Australia, Chile and other countries over the past decade have revealed how unprepared many policymakers and residents are for such rapidly moving infernos.
There are limits to preparation, though, in the era of megafires, according to experts. “Their speed and ferocity can create conditions that overwhelm even the most meticulously crafted plans,” the U.S. government warned in an evacuation guide released in June.
A UC Santa Barbara study published last month underscored the magnitude of the evacuation challenge, finding that 2.5 million people in the US live in small towns at high risk for wildfire but with limited escape routes. Researchers determined that fire fatalities are concentrated in such communities.
Nearly 18 million more people reside in places that face a lower though growing threat of wildfire but where there’s sometimes only one way out of town. Among them, Kentfield, California, a wealthy enclave 5 miles down the road from Fairfax that’s home to Gov. Gavin Newsom. It currently has moderate wildfire risk but only a few exits for its 6,900 residents, according to the study.
States like Florida, Hawaii and Oklahoma aren’t classified by the U.S. government as priority wildfire areas as they’re not heavily forested but the researchers discovered increasing evacuation risks there. Heat waves this year, for instance, have dried out vegetation that’s now fodder for fires started by a lightning strike, an errant spark from machinery or arson. Wildfires have burned nearly 204,000 acres in Florida so far in 2026.
In Oklahoma, increasing temperatures and drought have fueled a rise in grassland megafires since 2016. When Fong and her colleagues mapped communities with fewer than 50,000 people to wildfire hazards and lack of egress, they identified dozens of small towns across Oklahoma at high risk.
“That doesn’t necessarily align with most people’s narrative about wildfire being a Western problem,” said Fong, the paper’s lead author.
