After a 2010-2011 World Meteorological Organization investigation, an international panel of meteorologists has replaced the old most extreme temperature record, in the world 90 years to the date it was recorded.
The old record, 58 degrees Celsius, was recorded on September 13, 1922, at El Azizia, Libya. However, after their investigation, the panel, which included members from Argentina, Egypt, France, Italy, Libya, Morocco, Spain, the United Kingdom and the United States, found 5 inconsistencies with the record and chose to invalidate it.
"We found systematic errors in the 1922 reading," said Professor Randy Cerveny, who has been recording worldwide weather and climate records as the WMO's Rapporteur of Climate and Weather Extremes since 2006. "This change to the record books required significant sleuthing and a lot of forensic records work."
According to a WMO press release, the problems they found were: (a) problematical instrumentation, (b) a likely inexperienced observer, (c) an observation site over an asphalt-like material which was not representative of the native desert soil, (d) poor matching of the extreme to other nearby locations and (e) poor matching to subsequent temperatures recorded at the site.
They concluded that an inexperienced observer, who lacked training with an unsuitable and unreliable instrument that could easily be misread, improperly recorded the temperature, and therefore the record was off by about 7 degrees Celsius.
"This investigation demonstrates that, because of continued improvements in meteorology and climatology, climate experts can now reanalyze past weather records in much more detail than ever before. The end result is an even better set of climate data for analysis of important global and regional questions involving climate variability and change," said Cerveny.
Although the investigation began in 2010, it endured an 8-month delay after the team lost contact with one of their members, Khalid El Fadli, director of the climate section of the Libyan National Meteorological Center, right in the middle of the Libyan Civil War. El Fadli was forced to flee with his family when Tripoli came under attack, and was only able to send word to the WMO team 8 months later. There was another worrisome 3 week delay before he was able to contact them again and resume his part of the investigation.
"Khalid El Fadli did this at great risk to himself," Cerveny said. "He was an official of the previous regime, so when the revolution began to turn, his safety was a key concern."
With the 1922 record stricken from the books, the new Most Extreme Temperature Recorded is now 56.7 degrees Celsius, recorded on July 10, 1913 at Greenland Ranch — now called Furnace Creek Ranch — in Death Valley, California.
For a full list of weather and climate extremes, you can access the WMO Archive of Weather and Climate Extremes at this link.