America’s new normal temperature is one degree Fahrenheit higher than it was two decades ago.
Scientists have long pointed out that higher temperatures, changes in rain and snow patterns, and more extreme weather will be the new normal. Data released Tuesday by the US National Office for Oceanic and Atmospheric Administration (NOAA) put concrete figures on that pattern.
America’s new climate normal will not only be hotter, it will be more humid in the eastern and central regions of the country, and considerably drier in the west compared to a decade earlier.
Meteorologists calculate weather normals based on 30 years of data to limit random oscillations in daily weather. It is a standard set by the World Meteorological Organization. Every 10 years, NOAA updates the normals for the country, as well as for states and cities, by year, month and season.
For the entire nation, the annual normal temperature is now 11.8 ° C (53.3 ° F), based on data from weather stations from 1991 to 2020, which is almost half a degree Fahrenheit more than a decade ago. 20 years ago, the normal temperature was 11.3 ° C (52.3 ° F), based on data from 1971 to 2000. The average temperature for the United States during the 20th century was 11.1 ° C. (52 ° F).
The new normal annual temperature for the United States is 0.9 ° C (1.7 ° F) warmer than the first normal calculated for the period 1901 to 1930.
“Nearly every place in the United States has warmed from normal from 1981 to 2010 to normal from 1991 to 2020,” said Michael Palecki, director of the NOAA normals project.
The new normals are higher because the burning of fossil fuels is making the last decade “a much hotter period for much of the world than previous decades,” said Natalie Mahowald, a climatologist at Cornell University.