The Tale of NorthAM Temperature Highs
June’s major heat wave in the U.S. had the weather world buzzing with reports of hundreds of weather station record hot temperatures being set. Reports of new state record highs peppered the airwaves.
No doubt, it’s hot!
2012 is being called the hottest year on record.
July and now August have only brought more of the same. Hundreds more high temperature records set… more scattered reports of state record highs.
On Monday, specifically citing this summer’s heat wave, NASA climatologist Dr. James Hansen announced publication of new research:
“Research Links Extreme Summer Heat Events to Global Warming“
– Dr. James Hansen, NASA, 8/6/2012
The fact is, despite Hansen’s publication, there hasn’t been an increase in summer extreme heat events.
Data doesn’t support that allegation.
Yet we continue to hear alarmist media claims that it keeps getting hotter… year after year after year.
The “Summer Days” Temperature Anomaly
“Anomaly” is the scientific term used to describe the amount of departure from a defined average. If something is above the average its anomaly value is positive. If something is below the average its anomaly value is negative. The greater the departure, the higher (or lower) the value.
The chart above shows the North American “Number of Summer Days (tmax > 25ºC)” temperature anomaly. The data is maintained by NOAA’s U.S. National Climate Data Center (NCDC).
It plots the number of departures above or below the average number of summer days covering the time period from 1950 through 2006. The baseline average was calculated with data from 1955-1990. 2006 is the most current year that online data is released. 25ºC is 77 degrees Fahrenheit.
The reporting stations are color coded. Those with more summer days than the average over the 56 year reporting period are in “warm” colors – yellows to red. Those stations with fewer summer days than average are in “cool” colors – aqua to purple.
Plainly visible – in all its color coded glory – the earth has been cooling over the 56 year range, not warming!! Most stations report 5 FEWER summer days than the 1955-1990 average.
The alert alarmists among you might be jumping up and down screaming, “But… but… it doesn’t plot anything after 2006. 2007 and later are the hottest years on record!!!”
Then lets switch gears slightly to review only high and low temperature extremes… this time covering all years from 1880 up through and including this summer…
High and Low Temperature Extremes
This charts the number of U.S. state record high and low temperature extremes set or tied. They are tallied up and displayed by decade.
Properly verified and documented climate extremes are hard to come by. However, the NCDC does just that for the USA high and low temperature extremes. The chart plots their data.
The chart differs slightly from the NCDC dataset in two ways:
- Two records set on the same day in the same state is tallied as 1, not 2 records
- June’s 112ºF Georgia state record tying temperature, as yet unverified by the NCDC, is included
If the Georgia record tying temperature were not included then there would be no high temperature record extreme set in this decade.
There was another state record of 113°F reported for South Carolina during June’s heat wave. It is not included because the South Carolina State Climatologist does not expect it to be verified. A review of data and news reports for July and August did not find any further credible state high temperature extremes reported.
The bottom line
- By far, the 1930s is the decade with the most high and low temperature extremes since 1880
- Since 1999 there have been only 2 high temperature and 2 low temperature extremes set
- The decade of the 1910s has the 2nd highest number of hot extremes on record
- The decade of the 1990s is the second most active decade for both high and low extremes
- Contrary to popular belief, climate extremes have leveled off after 1999
The alert alarmists among you might be jumping up and down screaming, “But… but… what about Hansen’s research you just pointed out? That surely proves that, overall, its hotter now!!!”…
Hansen’s Latest Research
Last week, Alabama State Climatologist – Dr John Christy from the University of Alabama, Huntsville – testified before a U.S. Senate committee investigating climate change.
The Senate seeks to set Congressional policy to combat global warming.
In his written testimony Christy pointed out:
The recent claims about thousands of new record high temperatures were based on stations whose length-of-record could begin as recently as 1981, thus missing the many heat waves of the 20th century. Thus, any moderately hot day now will be publicized as setting records for these young stations because they were not operating in the 1930s.
– Dr John Christy, U.S. Senate Testimony, 8/1/2012
Reporting stations with collection histories younger than the 1930s are responsible for the hundreds of temperature record highs we’ve been hearing about from an alarmist media.
Hansen’s two data displays in his NASA report suffers from that built-in data bias.
Climate skeptic Andrew Watts reports that Hansen’s bell-curve graphic above suspiciously begins after the extreme heat of the early 20th century. It is further skewed by including the younger reporting stations. Hansen’s data also only includes northern hemisphere stations. All these things introduce bias into his dataset and conclusions.
Its a minor miracle that Hansen’s sloppy work survived peer review to get published at all.
When you peel back the veneer of sensationalist media reporting the sober facts appear.
The data is crystal clear.
No matter how you cut the mustard…
It ain’t gettin’ hotter faster. We ain’t gettin’ more high/low temperature extremes.