U.S. weather’s ‘new normal’ is a degree hotter

America’s new normal temperature is a degree hotter than it was just two decades ago.

Scientists have long talked about climate change — hotter temperatures, changes in rain and snowfall and more extreme weather — being the “new normal.” Data released Tuesday by the National Oceanic and Atmospheric Administration put hard figures on the cliche.

The new United States normal is not just hotter, but wetter in the eastern and central parts of the nation and considerably drier in the West than just a decade earlier.

Meteorologists calculate climate normals based on 30 years of data to limit the random swings of daily weather. It’s a standard set by the World Meteorological Organization. Every 10 years, NOAA updates normal for the country as a whole, states and cities — by year, month and season.

For the entire nation, the yearly normal temperature is now 53.3 degrees based on weather station data from 1991 to 2020, nearly half a degree warmer than a decade ago. Twenty years ago, normal was 52.3 degrees based on data from 1971 to 2000. The average U.S. temperature for the 20th century was 52 degrees.

The new normal annual U.S. temperature is 1.7 degrees hotter than the first normal calculated for 1901 to 1930.

“Almost every place in the U.S. has warmed from the 1981 to 2010 normal to the 1991 to 2020 normal,” said Michael Palecki, NOAA’S normals project manager.

Charlottesville, Va., saw the biggest jump in normal temperatures among 739 major weather stations. Other large changes were in California, Texas, Virginia, Indiana, Arizona, Oregon, Arkansas, Maryland, Florida, North Carolina and Alaska.

New normals are warmer because the burning of fossil fuels is making the last decade “a much hotter time period for much of the globe than the decades” before, said Cornell University climate scientist Natalie Mahowald.

For Phoenix, the biggest change in normal came in precipitation. The normal annual rainfall for Phoenix dropped 10 percent down to 7.2 inches. Rainfall in Los Angeles dropped 4.6 percent.

At the same time, Asheville, N.C., saw a nearly 9 percent increase in rainfall, while New York City’s rainfall rose 6 percent. Seattle’s normal is 5 percent wetter than it used to be.