Although the Death Valley reading was made 99 years ago, it is only now being recognized by the World Meteorological Organization as the most extreme high temperature ever recorded.
That's the result of a recently finished in-depth investigation of what had been claimed as the world record temperature extreme of 136.4 F, recorded on Sept. 13, 1922 in El Azizia, Libya.
The group found that there were enough questions surrounding the measurement and how it was made to suggest it was probably inaccurate.
"We found systematic errors in the 1922 reading," geographical science Professor Randy Cerveny of Arizona State University said.
"This change to the record books required significant sleuthing and a lot of forensic records work," said Cerveny, who also is the WMO official responsible for keeping worldwide weather records.
So now the official record returns to California and the 134 F recorded on July 10, 1913, at Greenland Ranch in Death Valley.
"This investigation demonstrates that, because of continued improvements in meteorology and climatology, researchers can now reanalyze past weather records in much more detail and with greater precision than ever before," Cerveny said. "The end result is an even better set of data for analysis of important global and regional questions involving climate change."