Posted on 11 July 2013 by Rob Honeycutt

There were also some random reports that Furnace Creek actually beat the previous 134°F with a new record of 135.5°F.  The official temperature on June 30, according to NWS, was 129.2°F.

Some alarm bells went off reading that the highest recorded temperature was in 1913.  Let's be skeptical on all sides and see where this leads us.

On the Weather Underground website I looked up the 1913 record and found the following footnote:

"The temperature of 134°F reported from Greenland Ranch on July 10, 1913 is most surely unreliable as is most of the pre-1920 Greenland Ranch heat data. The instrument shelter was unusually low to the ground and many of the record forms are inconsistent with other relevant stations and existing weather conditions. The hottest reliable temperature measured in Death Valley is 129°F which has occurred on four occasions: at Greenland Ranch on Jul. 20, 1960 and at Furnace Creek on Jul. 18, 1998, Jul. 20, 2005, and Jul. 7, 2007.These are also the hottest temperatures ever reliably measured anywhere in the world. For further discussion of the Greenland Ranch heat data see XXXXX. Amos (Mammoth Tank) recorded 130°F in Aug. 1887 but is most likely not a reliable reading."

So, it seems there might be some question about the validity of that figure.  We're not going to rule it out yet, just take it with a pinch of salt.

To get a general idea of the distribution of record high temps I pulled together a quick list of annual record high temps for the US since 1915 (because that's what was most easily available on Weather Underground).  I converted the temps to Celsius to group them a little better, and this was the result.

134°F is equivalent to 56.6°C.  That puts both the 134°F reading and the 135.5°F readings well out on the far end of the distribution.  In fact, 2°C past anything else recorded in the past 96 years in the US.

I contacted Dr Jeff Masters at Weather Underground and asked him about the Greenland Ranch record and he put me in contact with Chris Burt who is "the expert in these things."  

Chris is the extreme weather historian at Weather Underground and was kind enough to give me his views on the Greenland Ranch record.  Turns out, Chris actually wrote the footnote cited above, and added... 

"I am not as dubious of the 134° figure now as I used to be. It is still, however, very anomalous given that there were three 130°+ days that July of 1913, but no reading over 129° since then (almost yesterday [6/30], but no cigar!...)."

Chris says this "doesn't rule out that July 1913 could have been the result of a 500 year event."  So, it's possible that the Greenland Ranch record is accurate but, if it is, it's an extreme outlier.

The same thinking cuts both ways with regards to the claims that June 30 broke the old record.  Even though we've seen 5 record highs that reached 129°F globally since 1960, with four of those occurring since 1998 (1998, 2005, 2007 and now 2013), the 135.5°F figure would still be an extreme outlier, and thus somewhat suspect.

Another way of looking at just how anamolous 134°F (56.6°C) would be is to look at the trend of record high temps over time. Though the annual records I was able to collect at Weather Underground didn't extend back to 1913, you can still readily see how much 134°F and 135.5°F would stick out.

No Cigars in Libya either?

Some of you might recall that there was previously an extreme record high temperature reported for Azizia, Libya of 136.4°F (58°C) that occurred in 1922.  Again, since this would be such an anomolous outlier the reading came into question.  Chris Burt spearheaded the WMO investigation into the claim.  The results of the investigation determined that,

"...the 1922 El Azizia temperature extreme record, specifically (a) problematical instrumentation, (b) a likely inexperienced observer, (c) an observation site which was not representative of the desert surroundings, (d) poor matching of the extreme to other nearby locations and (e) poor matching to subsequent temperatures recorded at the site."

With that, the officially recorded high temperature on Earth remains at Death Valley with the 1913 record.

Blogging Extremes

We all have a natural proclivity for taking notice of record events.  A great place to get the nitty gritty on record extreme events is Chris Burt's Weather Extremes blog on Weather Underground.

Where I've done only a very cursory analysis of this recent heat event, Chris takes you into the nitty gritty of the influences that caused this event as well as how they record and confirm these record temperatures in this recent post.