PHOENIX (AZFamily) — New research suggests Arizona’s dry heat is deadlier than many think, and more deadly heat waves may be on the way.
Scientists have long used a humidity-heavy formula to identify the world’s deadliest heat waves, but this study says that formula may be dangerously overlooking dry climates like Phoenix.
Jennifer Vanos, an associate professor at Arizona State University’s School of Sustainability, who co-authored the research published on Nature Communications, examined six heat waves across the globe, including Phoenix’s summer of 2023, which shattered heat and death records across the Valley.
Dry heat proves just as dangerous
“We can say that extremely hot and dry conditions are found to be just as deadly as hot and humid conditions, but for very different reasons,” Vanos said.
Vanos said scientists have long relied on a metric called wet-bulb temperature to flag deadly heat. That metric heavily weighs humidity, but can miss how dangerous dry climates truly are.
“We were able to show the deadliness of the Phoenix heat wave that other models might not pick up because they’re not focused on the dangerousness of the dry conditions, and how the human body responds to that,” Vanos said.
Dan, who lives in Phoenix, is a Southern California native and says adjusting to Arizona’s heat took time.
“I’d rather have a dry heat than humid,” he said. “Less sweat.”
Heat safety recommendations
Vanos said shade and even misters can make a big difference in dry-heat cities like Phoenix.
“It’s super important to respect the heat and understand that heat affects everyone differently for different reasons,” Vanos said.
Vanos said every person reacts differently to different kinds of heat. With summer here, she recommends people check in on friends, family and neighbors to make sure everyone stays safe.
See a spelling or grammatical error in our story? Please click here to report it.
Do you have a photo or video of a breaking news story? Send it to us here with a brief description.
Copyright 2026 KTVK/KPHO. All rights reserved.