New Mexico getting hotter and drier

The latest U.S. Climate Normals – averaged over 30 years and updated every decade – show a slow climb in temperatures and a decline in moisture in the American Southwest, including New Mexico.

“In layman’s terms, it is warmer and drier in your neck of the woods in the 1991-2020 norms,” said Mike Palecki, physical scientist and climate normals project manager for the National Oceanic and Atmospheric Administration.

As a trend, the change in averages in the last three decades that indicate a warmer, drier Land of Enchantment are barely noticeable – except to farmers, river rafters, water managers, wildlife, plants and pastures. It doesn’t take much in an already dry geography for them to feel the impacts.

Steve Harris, longtime river guide and executive director of Río Grande Restoration, remembers the river’s heyday in the 1980s. That’s when the flows were legendary and river rafting gained steam as an industry in the region. But, Harris said, those huge flows that lasted through the summer have changed, marked by the benchmark drought year of 2002. Now the seasonal snowpack tends to be less in the mountains that feed the river and the warming temperatures have it melting off earlier, sending the peak flows down the river in March or early April, weeks earlier than in the past.

“If you look at the historical record, that’s not something that happened often before,” Harris said. “It’s a sign that things are coming unglued.”

The subtle temperature changes are easier to see at a more local level. A look at average tempera

ture in Taos County, for example, from January to April in the period 1895 to 2021, shows the fewest dips below freezing have occurred in the last 20 years. The graph of those temperatures is a steady upward climb. It doesn’t mean there aren’t super cold days well below freezing, but there are far fewer of them on average than in prior decades.

Warmer temperatures overnight, especially during the winter and spring, are another indicator of a worrying trend. When night and day temperatures together are warmer, the mountain snowpacks on which New Mexico rivers and streams depend melt quicker and any moisture dries up faster.

Scientists think small shifts in average temperatures over time can also cause wildlife species to shift as their habitats and food sources change.

Broken down month by month, the difference in averages for Taos is starker still. From 1981-2010, the average minimum temperature – generally night time temperatures – in January was 10.8 degrees Farenheit; from 1991-2020, the average minimum temperature for the month was 12.2 degrees. Overall average for the month was 26.6 from 1981-2020 and 27.1 from 1991-2020.

The average minimum for February from 1991-2020 was two whole degrees higher than from 1981-2010 and the overall average was a degree warmer.

In all but one month, minimum and overall average temperatures were warmer from 1991-2020 than from the 1981-2010 period.

“Overall temps including maximum and minimum for the Taos area have increased about .8 degrees over the last 30 years,” Palecki said. “That’s pretty substantial.”

The Climate Normals are tracked by NOAA along with other agency partners. Based on the latest climate norms “most of the U.S. was warmer, and the eastern two-thirds of the contiguous U.S. was wetter, from 1991–2020 than the previous normals period, 1981–2010,” according to NOAA’s

National Centers for Environmental Information.

The observations are based on more than 15,000 National Weather Stations and data gathered from trained on-the- ground observers.“The new normals period, 1991-2020, is the warmest on record for the country,” according to a statement from NOAA. “But warming is not ubiquitous across the contiguous U.S. in either geographic space or time of year. Changes vary from season-to-season and month-to-month.”

The first U.S. Climate Normals were calculated for 1901-1930 and have been updated every decade since.

Palecki said overall on an annual basis, New Mexico is one of the states that has warmed the most in the last 30 years.

Whether this a megadrought, the kind that can dry up water supplies altogether, last decades and force people to immigrate, as happened a few centuries ago in the region, remains to be seen.

Harris as an outdoorsman accustomed to adjusting to nature’s whims, thinks this changing climate is just another big challenge, like the recent pandemic, that humans will have to adjust to. “Nature is still with us. Nature is still functioning, by its own laws and logic,” he said. “We need to make the best of it.”

Find out more at ncei.noaa.gov/ products/us-climate-normals.