Death Valley's infamous heat record remains unbroken as summer ends

Earth has recently recorded its hottest day, month and year, but there’s one temperature record that remains oddly elusive: The world’s hottest temperature reading, a record infamously held by Death Valley.

Saturday marks the end of summer as meteorologists define it, and it's getting increasingly unlikely that the record will be broken this year.

Death Valley's record dates back over 100 years, to an unthinkably hot July day when temperature (reportedly) reached 134 degrees. And while California set the record for its hottest July this summer, Death Valley remained relatively far from its record.

Unlike many of Earth’s recent heat records – which are constructed of heat readings from around the globe – this record measures the temperature of a single location at a single point in time.

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That’s one reason Death Valley's record has become one of the most controversial in all of meteorology, with experts disagreeing about whether such a reading in 1913 was even possible.

Indeed, many longstanding record high temperature marks from decades ago have been met with skepticism in recent years, including a 1922 reading of 136.4 degrees in Libya which was officially discredited by the World Meteorological Organization in 2012.

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Citing previous climate research, climate scientist Randy Cerveny of the World Meteorological Organization told USA TODAY that 134 degrees might be close to the highest temperature our planet can reach.

But scientists aren't sure.

Paul Loikith, an associate professor of geography at Portland State University, said it's not currently known what Earth's highest possible temperature might be.

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"There is no easily defined physical limit on how hot it can get on Earth, so we can't readily apply some theoretical upper bound," Loikith said. Computer models may one day provide an answer, but it hasn't yet been seriously studied.

Whatever Earth's top temperature might be, the planet probably approaches it more often than we know.

"Remember that we can only record records where we have equipment and people,” Cerveny said.

"There are likely parts in the world (such as Northern Africa and the Middle East) where temperatures above 134 have already occurred … we just haven’t had surface equipment there to measure it," Cerveny said.

"Even in Death Valley there are likely hotter places such as Badwater Basin, where the National Weather Service just put a new sensor a couple of years ago."

Death Valley’s climate an ideal spot for a temperature record

Death Valley has a hellish summertime climate almost unlike any other spot on the planet: "With an average daily high of 115 degrees and a low of 87 during the month of July, Death Valley is far and away the hottest location in North America and perhaps the hottest place in the world," weather historian Christopher Burt writes in his book Extreme Weather.

Triple-digit temperatures are typical from the middle of May to very early October. The most sweltering days feature highs of 120 degrees or greater, the weather service reports.

The geography of Death Valley leads to many days where temperatures can vault within several degrees of 130 degrees, as they did in July, said meteorologist Bob Henson of Yale Climate Connections. (While the record of 134 degrees there is disputed, experts agree Death Valley has hit 130 degrees.)

It’s so consistently hot during the summer that it takes extreme conditions to spike the temperature in Death Valley: "In places like this — the hottest spots on Earth when averaged over long periods — there isn't a simple mechanism that can sharpen the existing heat peaks other than long-term global warming, which has added about 2 degrees to globally averaged temperatures over the past 100-plus years."

Did Death Valley really hit 134 degrees over 100 years ago?

This is a continuing debate among experts.

Count Burt among the skeptics. He told USA TODAY that "a temperature of 134 degrees in Death Valley on July 10, 1913, was essentially not possible from a meteorological perspective." The temperatures recorded at Death Valley during the period of hot weather from July 7-14, 1913, were not consistent with meteorological conditions during that time period, he said.

"There was no truly significant heat wave, let alone record-breaking, affecting the Southwest during that week," Burt said via e-mail.

Nevertheless, the World Meteorological Organization still insists that the 134-degree all-time world record is accurate. The WMO says this temperature may be the result of a sandstorm that occurred at the time. "Such a storm may have caused superheated surface materials to hit upon the temperature in the shelter," the WMO said.

Earth's hottest temperature will remain an elusive record

There are many flavors of record heat: scorching daytime highs, hot nighttime lows, record-long heatwave duration, and the like, Henson said. But keeping track of a single location's hottest temperature requires a special level of precision and patience.

"What we do know is that the range of possible weather on Earth or for any one location is much larger than we typically experience. Very rare, very extreme events occur, often at return intervals that are too long for us to capture them with our instrumental weather record," said Loikith.

"For example, if you took some location and monitored its weather for 100 years, you would see a range of possible temperatures including some extremes. But if you monitored it for 2,000 years, you would likely see extremes that you did not capture in the 100 year period."

He added that it is likely that an event like the 134 degrees at Death Valley is one of those extremes that recur very infrequently.

It would require a super-strong upper level high-pressure areas, said Henson. High pressure areas are usually associated with dry, hot weather because as the air sinks, it warms and the moisture evaporates, NOAA said.

Recently, those ingredients haven't aligned.

"The upper highs over California in July haven't been record-strong so much as relentless. Quite a few towns and cities in California are racking up their hottest month ever, because the heat has been so persistent and recurrent," Henson said. “So as human-produced warming continues, I think the bigger headlines will be normally milder places that get hotter than they've ever been, coupled with normally hot places that smash their records for lengthy periods of intense heat. Both situations can lead to extreme and dangerous health consequences.”

This article originally appeared on USA TODAY: Earth's hottest temperature: Death Valley's record still stands