Why some experts are skeptical about Death Valley's world record

Death Valley notched yet another record-high temperature, with the mercury soaring to 130 degrees Fahrenheit on Friday. The scorching temperature broke Death Valley's daily record for July 9 and cracked into the top five highest temperatures ever measured. The California valley now appears at least three times among the top five highest temperatures ever recorded on Earth, including a shared seat in third place.

The Friday temperature tied a record set on Aug. 16, 2020. Both temperatures share the third spot on the ranking and are subject to verification. The World Meteorological Organization (WMO) said on Monday that it would evaluate the 130-degree reading, as it's doing with the Aug. 16 reading from last year.

A sign warning visitors to Death Valley, Calif., of extreme heat. Temperatures were expected to soar well past 120 degrees on Wednesday, June 16, 2021, and for several days afterward.

Death Valley is also listed in the No. 1 spot with the highest temperature ever recorded on Earth at 134 degrees on July 10, 1913, holding on to the official world record.

But the all-time world record, which turned 108 years old on Saturday, is disputed by some in the weather community.

Christopher C. Burt, a weather historian at Weather Underground, published An Investigation of Death Valley's 134°F World Temperature Record in 2016, courtesy of William T. Reid -- a geographer and climatologist who has been studying Death Valley for decades.

The two came to the conclusion that "it was essentially not possible from a meteorological perspective" for Death Valley to reach 134 degrees on July 10, 1913.

Burt argues that the temperatures in the region don't match up with what was recorded at Death Valley in 1913. Burt also casts doubt on the observer who measured the temperatures on the sweltering July day.

AccuWeather Meteorologist Tony Laubach visited Death Valley, California, where temperatures as high as 130 were measured last week.

Weather observations in the region date back to 1891 when a temporary weather station was installed near Furnace Creek as part of a government investigation, wrote Arnold Court in a 1949 article published by the scientific journal The Geographical Review titled "How Hot Is Death Valley?"

In 1911, a cooperative station of the Weather Bureau, a precursor to the National Weather Service, was established at Greenland Ranch. The ranch, which sits 178 feet below sea level, is located in a relatively cooler area in the region.

The investigation argues that the temperatures recorded at Greenland Ranch in July 1913 were not consistent with other meteorological conditions in the region. There's no evidence of an exceptional heat wave in the southwestern U.S. at this time, Burt explained to AccuWeather.

The high temperatures cannot be attributed to "isolated hot spots," either, given the known meteorology of Death Valley during major heat events, according to the blog.

A sign warns of extreme heat danger at Badwater Basin, Monday, Aug. 17, 2020, in Death Valley National Park, Calif. Death Valley recorded a scorching 130 degrees (54.4 degrees Celsius) Sunday, which if the sensors and other conditions check out, would be the hottest Earth has been in more than 89 years and the third-warmest ever measured. (AP Photo/John Locher)

The atmosphere also wasn't hot enough to support a temperature as high as 134 degrees, according to Burt. The observer measured a series of high temperatures at Greenland Ranch from July 7-14, 1913, which ranged from 127 to 134 degrees, but the entire series did not match surrounding conditions.

Greenland Ranch's weather station also sits in an area of Death Valley that experiences relatively cooler conditions, according to the blog.

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"If the observations of 129°F to 134°F at Greenland Ranch from July 9 to 13 were authentic, then maximums at the closest surrounding stations during that 5-day period would have been substantially hotter than actually observed," according to the blog.

Burt also casts doubt on the observer's credibility, concluding that Oscar Denton, the Greenland Ranch caretaker who reported the 134-degree reading, lacked experience as an official U.S. Weather Bureau observer.

"It was so hot that swallows in full flight fell to the earth dead and when I went out to read the thermometer with a wet Turkish towel on my head, it was dry before I returned," Denton said of that fateful day, according to Death Valley National Park.

Denton could have "knowingly or inadvertently exaggerated" the highest temperatures, according to the blog. Perhaps, the conditions felt warmer than the thermometer showed, which led Denton to report a higher temperature, the blog speculated.

Court, who authored the 1949 paper on Death Valley, pointed out that the thermometer in use at the ranch was only graduated up to 135 degrees Fahrenheit. In a note accompanying the report at the end of the month, the observer stated that he doubted whether the record was high enough, adding that other thermometers at the ranch showed higher temperatures, according to Court.

But thermometers that are unprotected from sunlight often read much higher than those in weather shelters, Court adds. But Burt told AccuWeather there wasn't evidence of a siting issue.

Still, it's impossible to prove whether or not Denton "intentionally or inadvertently" altered his observations, concluding that the "best explanation" for the high temperature is observer error, according to Burt.

The Furnace Creek Visitor Center in Death Valley, Calif. Furnace Creek is the site where the world record high air temperature record was measured -- 134 degrees on July 10, 1913.

There's a history behind revisiting top-reported temperatures. In 2013, the World Meteorological Organization (WMO) reviewed and struck down a 136.4-degree temperature record reported in 1923 in Al Azizia, Libya.

The WMO moved to invalidate the 90-year-old record, citing problems with instrumentation, siting and observational procedures, according to the review, which was prompted by another blog entry published by Burt.

When the top-recorded figure was slashed, Death Valley's 1913 observation was boosted to the top spot. Burt told AccuWeather that the No. 2 spot -- 131 degrees in Kebili, Tunisia, in 1931 -- is also suspicious since the city is a green oasis.

Burt considers the latest temperatures observed in Death Valley to be "the hottest reliably measured temperatures on earth."

"The next strong El Niño year, there's a good chance it'll break its own record again and again, and who knows where it'll end?" Burt said. "It'll be a long time before it gets to 134, though."

Below, see a list of the top five highest temperatures ever measured.

1. 134°F in Death Valley, California, on July 10, 1913

2. 131°F in Kebili, Tunisia, in July 1931

3. 130°F in Death Valley, California, on July 9, 2021 and on August 16, 2020

4. 129°F Mitribah, Kuwait, on July 21, 2016 and Death Valley 8 times.

5. 129 °F Turbat, Pakistan, on 28 May 2017

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