Death Valley, California
The new heavyweight champion of the world (of weather records, that is)
90 years ago today—on September 13, 1922—a temperature of 58ºC (136.4ºF) was recorded at
El Azizia in Italian North Africa (modern-day Libya). That reading was, and has been ever since, the officially recognized hottest surface temperature ever recorded on the planet. It's arguably the most famous and iconic record in the world of weather; it's cited in countless textbooks and official documents; a
Google search on the subject returns a bazillion hits.
And as of this morning, Libya has been stripped of its title; that record is no longer valid.
A special investigative committee made up of international atmospheric scientists and weather experts convened by the World Meteorological Organization (WMO) spent many months researching the validity of the record, and finally announced their findings this morning in a peer-reviewed article published in the Bulletin of the American Meteorological Society (BAMS), summarizing as follows:
[T]he WMO World Archive of Weather and Climate Extremes has rejected this temperature extreme of 58ºC as the highest temperature officially recorded on the planet.
The article then goes on to conclude:
The WMO assessment is that the highest recorded surface temperature of 56.7°C (134°F) was measured on 10 July 1913 at Greenland Ranch (Death Valley) CA USA.
So there you have it: California is as of today
officially the hottest place on Earth. And now, should you be a true weather nerd or the type of person who's just generally interested in such things, the slightly convoluted story of how all this came about—complete with the prominent roles in the timing of the record's de-certification played by the
Arab Spring uprisings and the overthrow of
Muammar Gaddafi...
(DISCLOSURE: I was peripherally involved with that WMO investigative committee since shortly after it was created, performing research, analysis, and no small number of data visualizations. While I was not a member of that committee, nor am I an author of the BAMS article, my name—Jim Pettit—is attached to both the official WMO report and that article.)
The entire story is told with far greater detail and wit than you'll find here over in weather historian and New York Times bestselling author Christopher C . Burt's blog on Weather Underground; I urge you to visit for the entire tale, World Heat Record Overturned--A Personal Account. There's also a soon-to-be-aired half-hour documentary available for viewing at Weather Underground: Dead Heat: Overturning the World's Hottest Temperature. But for a brief summary, please read on...
The Azizia record has long been controversial; over the years, a number of curious people have hesitatingly looked into it, most coming to the conclusion that something about it didn't smell quite right. But there was never anywhere close to enough evidence to overturn the record, and there was a lot of inertia to keep it in place. And so it stood for nearly nine decades.
But then, back in March of 2010, Christopher C. Burt became involved in discussions about the Azizia record. These discussion led to an influx of new information, which Burt synthesized and published in a blog article challenging the record over on Weather Underground. That posting concluded:
The temperature observations at Al Azizia prior to 1927 (when the site and instruments were changed) are obviously invalid... It is likely that the absolute maximum temperature conceivable at the ['Azizia] site on this date was no more than 120°F at best.
Burt's article raised many poignant questions. And because of those questions, and both his weather expertise and his reputation as author of
the bestselling book Extreme Weather, a Guide and Record Book (
Amazon listing), the WMO decided to convene that investigative committee to research the record's validity.
One of the members of that committee (and participants in the earlier discussions) was Khalid Ibrahim El Fadli, the director of the Libyan National Meteorological Center (LNMC). It was El Fadli who uncovered one of the key documents that eventually led to the overturning of the record: the actual 1922 weather observer logbook from Azizia. El Fadli was extremely helpful in the gathering of information on the record, and he played a central—in fact, pivotal—role on the investigatory committee. So it caused great personal and professional alarm to the rest of the committee when he dropped from contact in March of 2011—right about the time Gaddafi initiated the violent last hurrah that culminated in his overthrow and death. In fact, up until El Fadli reconnected with members of the investigatory committee in August of 2011, some believed he may have been killed, just another of the many unfortunate victims of the widespread violence and brutality going on at the time (especially in light of some comments Gaddafi had made, as detailed in Burt's blog entry). As it turns out, El Fadli and his sons were indeed fired upon by Gaddafi's forces while riding in a car belonging to the UN.
But all's well that ends well, and this particular chapter ended well, indeed (though Gaddafi would likely disagree); after those many months of research and deliberation, the committee unanimously voted in January of this year to de-certify and disallow the Azizia record, and it was officially stricken from the books a short while ago. You can read a full scientific breakdown of the reasons for the disallowance in both the BAMS article and in Burt's blog entry, but in short, it came down to the following five areas:
- Instrumentation issues
- Observer inexperience
- Unrepresentative microclimate
- Poor correlation with contemporary regional temperature measurements
- Poor correlation with subsequent temperature measurements at that location
The upshot? As mentioned above, the hottest surface temperature ever accurately recorded in the world is now considered to be the 56.7°C (134°F) reading taken at Greenland Ranch (now called, perhaps more appropriately, Furnace Creek) in Death Valley on July 10, 1913—thus making California, as the headline states, the hottest place on Earth. That suits the marketing people at Death Valley National Park and the California board of tourism just fine—though it should be noted that, due to its new significance, that record is also under the preliminary phases of an investigation, as well. (However, almost all the data that have come in so far are leaning toward validating rather than disallowing that record.)
(Before I get flooded with complaints, yes, I realize there are certainly other places around the globe with higher annual mean temperatures than Death Valley, just as there are still other locations with, say, a greater number of annual days over 100 degrees. And so on. Calling California the hottest place on the planet is simply based on the fact that the Golden State is the official home of the highest regular surface temperature ever accurately measured. California, FTW!)