Heat waves will hit the West much more often 30 years from now, analysis shows
New research suggests that as the prevalence of extreme heat events spike over the next 30 years, the odds of heat waves hitting the West Coast and Mountain West will be higher than in most of the rest of the country.
That's one of the findings in a report published this week by the First Street Foundation, a nonprofit research group that analyzes climate risk in the U.S. The group modeled the frequency and duration of hazardous heat events three decades from now, including localized projections.
Researchers identified the seven hottest days that will occur in a location this year, be it Boise or Denver, and then applied its climate-adjusted heat model to estimate how many extremely hot days there will be in 2053. The results show that the country should expect a big increase in hot days, which increases the chances of heat waves.
Bradley Wilson, the foundation’s director of research and development, is one of the authors of the report. He says on average they saw "local hot days" – defined as those above the 98th percentile for temperature – at least doubling across the country in the years to come.
“A lot of people think about what the weather has been for the past 30 years — what a hot day is like in their area, like this July has been really hot in a lot of places,” Wilson said. “I think those kinds of temperatures are going to start to become more normal.”
They used multiple data sets, including land surface temperatures, canopy cover, and proximity to water to establish current temperature conditions then used forecasted emissions scenarios to predict conditions in 2053, according to a press release.
In that time period, the counties across the Mountain West expected to experience the largest increase in local hot days are Las Animas in Colorado, Doña Ana in New Mexico, Piute in Utah, Platte in Wyoming, Beaverhead in Montana, Owyhee in Idaho and Esmeralda in Nevada — sometimes tripling or almost quadrupling in frequency. Depending on the location, these may include “Health Caution Days” with temperatures that feel 90 degrees or more, or “Dangerously Hot Days” that feel at or above 100 degrees.
Wilson says these longer heat waves have been connected to illnesses like heat fatigue, stroke and death. Increased heat can also impact infrastructure as it melts runways or swells bridge joints.
“Increasing temperatures are broadly discussed as averages, but the focus should be on the extension of the extreme tail events expected in a given year,” said Matthew Eby, CEO of First Street Foundation. “We need to be prepared for the inevitable, that a quarter of the country will soon fall inside the 'Extreme Heat Belt' with temperatures exceeding 125°F – and the results will be dire.”
First Street Foundation also added a tab to their online tool Risk Factor to identify heat risk by address. For example, a property near KUNM, an NPR member station in Albuquerque, N.M., was rated a “major heat factor.” At this site a hot day feels like it’s 95 degrees or above. In 2022, six hot days are expected. In 2053, the model forecasts 14.
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.