A Vivid View of Extreme Weather: Temperature Records in the U.S. in 2021

The New York Times

A Vivid View of Extreme Weather: Temperature Records in the U.S. in 2021

Krishna Karra and Tim Wallace January 15, 2022

SHAVER LAKE, CA – JULY 15: In an aerial view, a barren landscape is seen after burned trees were cut down following the Creek Fire, which began on September 4, 2020 and was fully contained on December 24, on July 15, 2021 near Shaver Lake California. The 379,895-acre fire was the fourth largest recorded in California and the biggest single fire that was not part of a greater complex fire. Hundreds of homes were destroyed and scores of backpackers the path of the fire were airlifted from the wilderness in the Sierra Nevada mountains. At one point, about 1,000 people were trapped near Mammoth Pool Reservoir with more than 200 on a boat launch. Authorities are bracing for a predicted driest year on record for the Kern River, carrying only about a quarter of the average Sierra snowmelt water to Lake Isabella. Large portion of the West are now in the most extreme drought category and fire officials are warning of another devastating wildfire season in California. (Photo by David McNew/Getty Images) (David McNew via Getty Images)

Temperatures in the United States last year broke more records for the hottest or coldest ever documented than any other year since 1994, according to a New York Times analysis of Global Historical Climatology Network data.

Heat waves made up most of these records, setting a new mark at 8.3% of all U.S. weather stations, more than in any year since at least 1948, when weather observations were first digitally recorded by the federal government.

The world has been warming by almost two-tenths of a degree per decade. Extreme-temperature events can often demonstrate the most visible effects of climate change.

“We do not live in a stable climate now,” said Robert Rohde, the lead scientist at Berkeley Earth, an independent organization focused on environmental data science. “We will expect to see more extremes and more all-time records being set.”

The brutal arctic outburst that caused Texas’ power grid to fail and the heat wave in the Pacific Northwest in June account for many of the records.

During the winter storm, on Feb. 17, the temperature dropped to minus 5.98 degrees in Jacksonville, Texas, far below its normal February low of about 40 degrees. State officials in Texas said that 246 people died in the storm.

In Salem, Oregon, the temperature spiked to 116.96 degrees on June 28. The normal high there in June is around 74 degrees. The National Weather Service has attributed at least 110 deaths to the extreme heat.

The Times analyzed temperature data from more than 7,800 weather stations across the United States. Locations without at least 30 years of weather data were ignored, though most stations have recorded temperature for at least 65 years.

Records have been set somewhere in the country every year since at least 1970, but 2021 stands alone when compared with recent years, a Times analysis found.

Heat waves in 2002 and 2012 brought extreme temperatures to hundreds of cities and towns. Like 2021, 2011 broke numerous cold and heat records. But last year’s extreme temperatures were spread across large areas of the country and surpassed even more records.

Numerous records set in 2021 were also broken by double digits.

To explain these extremes, Rohde made a comparison with world records in the 100-meter dash. Runners typically break world records by hundredths of a second.

Among the new temperature records, Rohde said, “it’s like someone came in and seemed to be running an entirely different race because they just blew past everything we’ve come to expect.”

New marks were also set by breaking records that have stood for decades. Bottineau, North Dakota, set a new minimum temperature record of minus 50.98 Fahrenheit, eclipsing tens of thousands of daily observations since 1893.

According to experts, climate change has pushed the extremes of temperature ranges around the world.

“What were hot days in the past are becoming more common,” Rohde said. “What were very, very hot days in the past are now two or three times more common than they used to be.”


Data in the United States was obtained from the Global Historical Climatology Network (GHCN), an integrated database maintained by NOAA that contains daily climate summaries from land surface stations. The data was processed and analyzed with BigQuery.

The GHCN daily data set acts as the official weather record of the United States, and it has been validated for spatial and temporal consistency across measurements. Daily observations that failed any quality checks were excluded, such as measurements that far exceed the lowest or highest temperatures ever recorded on Earth.

A historical record is defined as the hottest or coldest temperature ever recorded up to that date. Only the hottest or coldest record for a particular year is compared. Other records in the same year, like, for example, during an extended heat wave, are excluded.

For every historical record, only stations that have collected a minimum of 30 years of data are used. Further, each station included in our analysis is required to have collected data for a minimum of half of its life span.

To compute historical records for cities, stations were aggregated to incorporated places as defined by the U.S. Geological Survey. Within each area, data across stations is treated as a unified measurement for calculating historical records. Records may differ slightly from other aggregated sources based on the specific regions and stations considered.

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Author: John Hanno

Born and raised in Chicago, Illinois. Bogan High School. Worked in Alaska after the earthquake. Joined U.S. Army at 17. Sergeant, B Battery, 3rd Battalion, 84th Artillery, 7th Army. Member of 12 different unions, including 4 different locals of the I.B.E.W. Worked for fortune 50, 100 and 200 companies as an industrial electrician, electrical/electronic technician.