Since 1970, the annual number of freezing nights in Reno, Nev., has decreased by 91. That’s the largest decline in the nation, according to research group Climate Central, which recently analyzed trends in the number of coldest nights each year from 1970 to 2022.
Ranking second is Albuquerque, N.M., with 45 fewer freezing nights. Other notable decreases in the Mountain West include Helena, Mont. (30 fewer), Boise, Idaho (16 fewer) and Salt Lake City, Utah (13 fewer).
Steph McAfee, the Nevada state climatologist, said while warming winters can reduce heating costs and risks to vulnerable people, they raise major concerns.
“If it’s not getting cold at night, that snowpack up in the mountains melts out faster,” McAfee said. “And this is a concern for us, because wintertime snow are where most of our water comes from in Reno and in places like Las Vegas.”
McAfee said this can also hurt farmers’ crops as a lack of winter cold can allow some insect populations to grow, resulting in more of them to harm crops in the spring and summer.
Economies that rely on winter recreation feel the pain, too, she said. Warming winters can disrupt snowfall patterns, making it difficult for ski resorts to maintain snow and ice.
McAfee expects winters to continue warming from heat-trapping greenhouse gases. In fact, some areas that used to experience freezing nights rarely do, like Las Vegas, Nev., and Phoenix, Ariz.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Nevada Public Radio, Boise State Public Radio in Idaho, KUNR in Nevada, the O'Connor Center for the Rocky Mountain West in Montana, KUNC in Colorado, KUNM in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.
