April 2017 Most Extreme U.S. Temperatures

In previous posts on this site and on Weather Underground I introduced the weather and climate world to the concept of an Extreme Temperature Index. Lets apply the current index algorithm to reports from April 2017 in the National Center for Environmental Information’s surface records site and see what the most extreme event and location was. Keep in mind that these are not the hottest and coldest records, but the records that differed farthest from the norm, climatologically. Drop me a note if you think you have spied a more extreme record and its location than what is presented here for April.


and: https://guyonclimate.com/2017/03/24/extreme-temperature-index-some-calculations-and-comparisons/


The current Extreme Temperature Index is defined by:



In the ETI equation the difference between the old and new record is the most predominant factor,  so I have selected a record low minimum and record high maximum with the highest T sub r.

The big cold winner was Cuthbert, GA, which broke their old record low minimum by 14 degrees. Oklahoma City, OK, also broke their record by 14 degrees, but had a much shorter period in which that station had been keeping records (Period of Record…POR or n). I took the norms, or average high and low for the date the new record was set, for April 29th, from the closest large major city, Columbus, GA:


Now for the hot record. Tully Lake, MA broke their record by 15 degrees. They got up to 90 on 4/12. I’m using the norms from Worchester, MA, the closest large city:



There is no surprise that the ETI top value for the coldest and hottest records based mainly on difference between the new and old records goes to the hot record since April 2017 was a warm month, overall. So far, the total of record daily high maximums for April were 989 vs. only 213 record daily low minimums.

The top ETI prize goes to Tully Lake, MA for April 2017. I am sure that the residents there were shocked to see mid-summer warmth there on April 12th. Carbon pollution should lead to future high ETI values.

The Climate Guy


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