The period from June through August this year was the hottest on record in the United States, exceeding even the Dust Bowl summer of 1936, the National Oceanic and Atmospheric Administration said Thursday.
The average temperature this summer in the contiguous United States was 74 degrees Fahrenheit (23.3 degrees Celsius), exceeding by less than a hundredth of a degree the record set in the summer of 1936, when scorching heat led to the death of thousands of Americans and catastrophic crop failure.
Five states — California, Idaho, Nevada, Oregon and Utah — reported their warmest summers on record, NOAA reported, while 16 other states reported “a top-five warmest summer on record,” the agency said.
The average temperature in the United States through August this year was 55.6 degrees, NOAA said, 1.8 degrees above the 20th-century average and the 13th warmest to date for that period of the year.
On Thursday, many areas in the West remained under an excessive heat warning, including portions of Southern Nevada, Death Valley, the Colorado River Valley and eastern San Bernardino County, California, the National Weather Service said. Temperatures were expected to range from 105 degrees in Las Vegas to nearly 120 degrees in Death Valley.
While tying a single heat wave to climate change requires extensive attribution analysis, heat waves around the world are growing more frequent, longer-lasting and more dangerous. The 2018 National Climate Assessment, a major scientific report issued by 13 federal agencies, notes that the number of hot days is increasing, and the frequency of heat waves in the United States jumped from an average of two per year in the 1960s to six per year by the 2010s. Also, the season for heat waves has stretched to be 45 days longer than it was in the 1960s, according to the report.
It is all part of an overall warming trend: The seven warmest years in the history of accurate worldwide record-keeping have been the last seven years, and 19 of the 20 warmest years have occurred since 2000; worldwide, June 2019 was the hottest ever recorded and June 2020 essentially tied it.
NOAA included the details of this summer’s record-setting temperatures in its monthly climate report, which it issued near the end of a summer of extreme weather events in the United States.
Hurricane Ida made landfall in Louisiana on Aug. 29 with sustained winds of 150 mph, making 2021 the second year in a row that a Category 4 hurricane slammed the state, NOAA said.
Three days later, Ida’s remnants tore across the Northeast, causing deadly flash flooding that was blamed for dozens of deaths. Ida followed soon after Tropical Storm Fred caused flash flooding and touched off several tornadoes in the Southeast, and after Tropical Storm Henri brought fierce wind and torrential rain to much of the Northeast.
Water wasn’t the only problem. Wildfires devastated large swaths of California. The Dixie Fire, which started in July, has destroyed more than 927,000 acres and is now the second-largest fire in the state’s history, NOAA said. The Caldor Fire also grew quickly in August and threatened communities southwest of Lake Tahoe in California.
This article originally appeared in The New York Times.