GWPF Exposes EPA Deception in New Climate Change Heat Wave Index

Guest essay by Larry Hamlin

The Global Warming Policy Forum (GWPF) published a comprehensive article addressing new U.S. EPA (Environmental Protection Agency) climate change indicators allegedly made to inform science-based decision-making but instead found that many of these indicators are misleading, deceptive, incomplete and based on selective data.

The GWPF article specifically addressed recent shenanigans by the EPA involving its heat wave climate change indicators which supposedly portray heat wave frequency in the U.S from 1961 to 2019 as shown below.

The GWPF notes the heat wave frequency data presented by the EPA (red data on the left) is misleading because it shows (without specifically identifying as such) minimum not maximum temperatures across 50 American cities. The GWPF data (blue data on the left) shows the maximum temperatures which greatly reduces the heat wave frequency derived from the 1960 and beyond period.

Additionally, as noted by GWPF the EPA data excludes the prior global cooling period from 1940 to 1970 thus exaggerating the warmer period that occurred after that time and more significantly ignores the extensive and searing heat of the 1930s period.        

Prior to these recent climate change indicator changes the EPA website presented the heat wave index as shown below for the period 1895 to 2015 (identified under the “High and Low Temperatures” heading) which clearly displayed the heat wave dominance of the period of the 1930s as well as the absence of increasing heat wave trends since that time.

But the EPA’s latest updated version has the climate change heat wave indicators presented as follows in a completely changed format under the heading “Heat Waves” which was a heading category not identified in the prior EPA version with the GWPF article exposing the deliberately and grossly misleading nature of these alleged heat wave indicators.

The prominent heat wave decadal period from 1930 to 1940 was omitted from this latest EPA change and the heat wave index appearing in the prior EPA version was “de-emphasized” (disappeared) by placing it in a tiny thumb scale graph as shown below labeled Figure 3.

The full-sized Figure 3 displaying the heat wave index as provided in the prior EPA version is updated from 1895 through year 2020 (versus 2015) and shown below which continues to show the period of the 1930s dominating U.S. heat waves as well as showing no significant increasing heat wave trends since the period of the 1930’s.

Additionally, the “High and Low Temperatures” heading heat wave index graph from the earlier EPA version was replaced with the graph below presenting hot and low daily highs by percent of land area over the period 1985 to year 2020 as a dishonest attempt to conceal the clearly dominant heat wave period of the 1930s.

The GWPF article addresses the U.S. Fourth National Climate Assessment report that provides data on both heat wave duration and average maximum temperature during any given heat wave since 1900 as shown in the graphs below. This data demonstrates that the heat wave duration has declined by 41% since the 1930s and that the average maximum heat wave temperature has declined from 101 degrees F in the 1930s to 99 degrees F since the 1980s.

There are numerous temperature and heat wave climate data sources which establish the dominance of the earlier time periods (the 1930s) as being far warmer with greater heat wave intervals than the present and which expose the lack of credibility of climate alarmist claims that we are experiencing greater numbers and higher heat wave temperatures now than in the past as shown in the data below.

The GWPF article concludes with the following conclusion regarding the EPA’s efforts at misleading the public about heat waves in its latest changes as follows:

What all this means is that the EPA’s heat-wave indicator grossly misrepresents the actual science and defeats its stated goal for the indicators of “informing our understanding of climate change.”

Welcome to the Biden era of climate science distortion, deception and dishonesty for purposes of fabricating political propaganda in support of scientifically unsupported climate alarmist mandates for Americans.    

5 40 votes
Article Rating
107 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
May 26, 2021 6:14 am
Reply to  Steve Case
May 26, 2021 11:08 am

You can still find it here on the Wayback machine or there’s a pdf here

It’s just harder to find

Bryan A
Reply to  Redge
May 26, 2021 11:53 am

Valid data tells lies…
Valid data tells lies…
Valid data tells lies…
Valid data tells lies…
Valid data tells lies…
Valid data tells lies…

There, I feel better now

Bindidon
Reply to  Steve Case
May 26, 2021 3:48 pm

Steve Case

Redge found the stuff, but for you, real links might better than hidden anchors:

https://www.fs.fed.us/research/sustain/docs/indicators/indicator-316.pdf

It seems that some people here (Larry Hamlin himself included) have such difficulties to find data that when they fail to find, they immediately start suspecting somebody hiding it.

Great!

J.-P. D.

Bindidon
Reply to  Steve Case
May 26, 2021 5:23 pm

If anybody wanted to get things disappear, s/he just would need to erase data we need to see what happened.

Sorry for those suffering a bit under paranoia: the data still is there, beginning with temperatures recorded by weather stations, in CONUS and elsewhere.

The very first proof is that e.g. UAH’s John Christy easily could use it to present his opinion concerning extreme high and low temperatures in CONUS.

Recently, he repeated an exercise he first made in 2018, in which he had shown the distribution of daily maxima recorded by USHCN stations, indicating in his opinion that there would be currently no significant warming in the contiguous US in comparison with earlier, warmer periods, because the years with the highest numbers of maxima per station appeared in earlier times, especially in the 1930’s.

The focus of John Christy’s new paper was this time to demonstrate, by using a very similar scheme, a decrease of both extreme hot and cold events in CONUS (his paper about that is available only in the Web Archive):

https://tinyurl.com/11wxlmzl

So you can see: nothing disappears that quick.

But… in his evaluation, I miss something: namely how, near the lowest minima, the highest minima do behave.

It’d had been easy to make a third bar chart showing that. Instead, I thought it would be better to use as always line plots instead of bars, allowing us for easier comparison.

Moreover, all values were uniformly scaled to percentiles, making comparisons between both plots in a graph and among graphs even easier.

Here you see a graph with data very similar to John Christy’s, but using GHCN daily station data instead of USHCN, using stations with at least 100 years of data as well:

comment image

And here you see why I wanted to collect high minimas: together with the highest number of maxima per year, recorded in 1934 and 1936, you see also the highest number of highest minima.

And while the maxima and the lowest minima decrease over time since the 1970’s, the highest minima don’t. Why? No se!

*
Let me conclude with an extension of John Christy’s analysis from CONUS up to the Globe, of course still using stations with at least 100 years of data.

A first chart, made in the same way as that for CONUS above, shows this:

comment image

Oooh! Some will say. ” The Globe looks like CONUS, as I expected. ”

Sorry for disappointing. In the graph above, the CONUS stations account for about 80 % of the data… letting the Globe appear like CONUS’ backyard.

When applying an area weighting scheme on the base of a 2.5 degree grid, the data is first averaged in grid cells before computing the yearly averages.

We then see this instead:

comment image

Yeah. Draw you own conclusions!

J.-P. D.

Tom Halla
May 26, 2021 6:14 am

If someone does not show all the available data in a historical graph, it is being done for dishonest reasons. It is a clear indication they are cherry picking.

DrEd
Reply to  Tom Halla
May 26, 2021 7:30 am

Biden has his liars and bullsh**ers working overtime now.

Forrest Gardener
Reply to  DrEd
May 26, 2021 10:32 pm

Agreed that the liars and bulltishers are working overtime but I doubt very much that Biden is playing any active part on any of this.

2hotel9
May 26, 2021 6:29 am

“many of these indicators are misleading, deceptive, incomplete and based on selective data.” So, EPA is simply lying to push their leftist political agenda. Got it.

Bruce Cobb
May 26, 2021 6:34 am

Has the new Climate Change Liar Index come out yet?
Asking for a friend.

May 26, 2021 6:36 am

Here’s the Wikipedia page on the Dust Bowl
No mention of heat waves in the text, but in the references you can find this:
1936 North American heat wave

It’s always interesting to see how recently the Wikipedia page was edited.
The dustbowl page was edited last night and the 1936 Heat wave page two weeks ago.

Reply to  Steve Case
May 26, 2021 9:00 am

Grapes of Wrath will soon be out of print.

another ian
Reply to  mkelly
May 26, 2021 4:00 pm

Recalled and pulped?

Bindidon
Reply to  Steve Case
May 26, 2021 4:00 pm

Steve Case

Nonsense.

The Dust Bowl was a mix of temperature, drought and wind. The North American heat wave was something quite different, much more based on temperature alone.

If you were able to process data out of e.g.

ftp://ftp.ncdc.noaa.gov/pub/data/ghcn/daily/

for CONUS, such that you see temperatures at 2.5 degree grid level, you would immediately understand the difference between the two: the highest temperatures were NOT recorded within the Dust Bowl area in the 1930’s.

And what concerns “edited last night”: what about looking in the page’s history, Mr Case, before softly insinuating some manipulation?

Oh I know, I’ll be again downvoted a lot because I simply say the… truth.

Great.

J.-P. D.

Forrest Gardener
Reply to  Bindidon
May 26, 2021 10:34 pm

Shame you used an ellipsis to hide the words “opposite of”.

Tom Abbott
Reply to  Bindidon
May 27, 2021 3:51 am

“the highest temperatures were NOT recorded within the Dust Bowl area in the 1930’s.”

Where were the highest temperatures recorded? Death Valley?

Bindidon
Reply to  Tom Abbott
May 27, 2021 1:38 pm

Tom Abbott

When you look at such places at a given time, it won’t help you to look at absolute temperatures. Death Valley is nearly always warmer than the rest.

You have to take anomalies wrt the mean of a common period instead.

Then you see that while the Death Valley anomalies keep flat, others don’t.

I checked that years ago, and sorry: it took me a lot of time I won’t reinvest anymore.

To start the job, you have to select, out of e.g. GHCN daily, all stations available within

comment image

with a sufficient lifetime, and compute for them the anomalies wrt e.g. 1951-1980.

*
At that time, I did the same for France, to look at what happened there in 2003.

The heat wave in 2003 has shown the same as 1934/36 for CONUS: highest number of maxima observations PLUS highest number of highest minima observations.

J.-P. D.

Reply to  Bindidon
May 27, 2021 5:08 am

a mix of temperature, drought and wind

That looks like “extreme weather” to me. I thought we only got extremes now we produce all those evil see-oh-toos? It’s almost as if climactic extremes have always been around and there’s nothing out of the ordinary with our weather today, doesn’t it?

Bindidon
Reply to  Andy Wilkins
May 27, 2021 1:42 pm

Andy Wilkins

You seem to be fixated on CO2; I’m not, and didn’t mention it in any comment on this thread.

J.-P. D.

Reply to  Bindidon
May 27, 2021 1:45 pm

I love a bit of CO2, me. Fantastic plant food.

Jim Clarke
May 26, 2021 6:47 am

The actual goal of the EPA is the same goal of all Federal Agencies…The preservation and expansion of the agency. The climate crisis narrative is ‘miracle grow’ for the EPA, so the EPA will do anything to support that narrative, regardless of the number of neo-Marxists and Luciferians that are employed by the agency. Of course, the more of those types they have just exacerbates the problem.

Weekly_rise
May 26, 2021 7:00 am

The GWPF notes the heat wave frequency data presented by the EPA (red data on the left) is misleading because it shows (without specifically identifying as such) minimum not maximum temperatures across 50 American cities. The GWPF data (blue data on the left) shows the maximum temperatures which greatly reduces the heat wave frequency derived from the 1960 and beyond period.

It’s unclear to me how using the minimum daily temperatures in calculating heat wave numbers would be misleading.

Bruce Cobb
Reply to  Weekly_rise
May 26, 2021 7:07 am

Apparently, minimums have risen, whereas maximums haven’t really.

Weekly_rise
Reply to  Bruce Cobb
May 26, 2021 7:09 am

There appears to be a clear trend in both the minimum and maximums, but even were that not the case it wouldn’t make the use of the minimum daily temperature wrong or misleading. If you defined a heat wave as “4 or more days where the average of the minimum daily temperature exceeds what would have been expected based on the previous decade” or if you define it as “4 or more days where the average of the maximum daily temperature exceeds what would have been expected based on the previous decade” you’re producing two slightly different metrics, but both show real and relevant information.

Reply to  Weekly_rise
May 26, 2021 8:17 am

Rather than using just the minimum or maximum- why not average the temperatures throughout the day- say hourly- and use that figure?

Weekly_rise
Reply to  Joseph Zorzin
May 26, 2021 8:34 am

I suspect the reason is because it is the extremes that matter most for heat waves, and it matters what time of day the unusual heat is occurring. Daily minimum temperature will reflect high night time temperatures, daily max will reflect high daytime temps.

Reply to  Weekly_rise
May 26, 2021 8:44 am

Perhaps- but, I should think that the extent to which hot weather is drying out your local environment, an average temperature would give the most useful information. Maybe giving the lows, the highs, and the average would be the ultimate in data detail.

Reply to  Joseph Zorzin
May 26, 2021 10:42 am

And the standard deviation. Yes, I agree.
Have an upvote

Ian W
Reply to  Joseph Zorzin
May 26, 2021 2:01 pm

Averaging an intensive variable like atmospheric temperature is mathematically simple but a nonsense scientifically.This is because of the varying enthalpy with humidity ask any HVAC engineer.

The correct metric is kilojoules per kilogram which is a direct measure of the heat content of the volume of air.

meab
Reply to  Joseph Zorzin
May 26, 2021 11:20 am

Ever hear of the guy that had one hand in a pot of boiling water and the other in ice water? On average his hands felt just fine.

Reply to  meab
May 26, 2021 6:02 pm

Think that one up by yourself?

Not a temperature measurement.

Dave Fair
Reply to  Weekly_rise
May 26, 2021 9:42 am

Increasing minimum temperatures are an indication that the climate is getting milder, not an indication of increasing heatwaves.

Weekly_rise
Reply to  Dave Fair
May 26, 2021 9:52 am

The graph is not a graph of minimum temperatures, but a graph showing counts of heatwaves defined by unusually hot minimum temperatures.

Dave Fair
Reply to  Weekly_rise
May 26, 2021 10:14 am

How much are you being paid to play the fool here on WUWT?

Clyde Spencer
Reply to  Weekly_rise
May 26, 2021 8:47 pm

“4 or more days where the average of the minimum daily temperature exceeds what would have been expected based on the previous decade”

That would fail in the Wintertime.

Weekly_rise
Reply to  Bruce Cobb
May 26, 2021 7:14 am

Also the website does indicate pretty clearly that it is using daily minimum:

Heat waves can be defined in many different ways. For consistency across the country, Figures 1 and 2 define a heat wave as a period of two or more consecutive days when the daily minimum apparent temperature (the actual temperature adjusted for humidity) in a particular city exceeds the 85th percentile of historical July and August temperatures (1981–2010) for that city. This definition is useful for several reasons:

  • The most serious health impacts of a heat wave are often associated with high temperatures at night, which is usually the daily minimum.5 The human body needs to cool off at night, especially after a hot day. If the air stays too warm at night, the body faces extra strain as the heart pumps harder to try to regulate body temperature.
  • Adjusting for humidity is important because when humidity is high, water does not evaporate as easily, so it is harder for the human body to cool off by sweating. That is why health warnings about extreme heat are often based on the “heat index,” which combines temperature and humidity.
  • The 85th percentile of July and August temperatures equates to the nine hottest days in a typical summer. A temperature that is typically only recorded nine times during the hottest part of the year is rare enough that most people would consider it to be unusually hot.
  • By using the 85th percentile for each individual city, Figures 1 and 2 define “unusual” in terms of local conditions. After all, a specific temperature like 95°F might be unusually hot in one city but perfectly normal in another. Plus, people in relatively warm regions (such as the Southwest) may be better acclimated and adapted to hot weather.

So it is both clearly documented and well justified.

Reply to  Weekly_rise
May 26, 2021 7:48 am

Weekly_rise posted: So it is both clearly documented and well justified.”

Well, as to the claim “clearly documented”, I would note yes, as in reading the fine print of a 30+ page contract.

As to “well justified”, I would note only if one overlooks the obviously bias-revised, manipulative wordings (clearly documented in excerpts from the GWPF-published comprehensive article) that are given in the above article.

They have eyes to see but do not see . . .” — Bible (NIV), Ezekiel 12:2

Jon R
Reply to  Gordon A. Dressler
May 26, 2021 10:31 am

None is so blind as he who refuses to see.

Reply to  Weekly_rise
May 26, 2021 8:00 am

Not. Of this entire screed, adding in the effects of humidity is the only “justified” change to the definition (although that is a curve with an inflection point – extreme dryness is just as bad, physiologically, as extreme humidity). The remainder is pseudo-scientific bafflegab (“Scientism,” in short) to “justify” the substitution of daily minimum for daily maximum.

I note that you do not dare to address the blatant cherry picking of eliminating all measurements before 1960.

Weekly_rise
Reply to  writing observer
May 26, 2021 8:18 am

The EPA website describes the reason for using post-1960 data for two of the graphs:

Temperature data are less certain for the early part of the 20th century because fewer stations were operating at that time. In addition, measuring devices and methods have changed over time, and some stations have moved. The data in Figure 3 have been adjusted to the extent possible to account for some of these influences and biases, however, and these uncertainties are not sufficient to change the fundamental nature of the trends.

For Figures 1 and 2, the sparsity of data makes the early years very uncertain, but the trend for the heat wave index in graph 3 is so pronounced that the sparsity of data has less of an impact. Additionally, Figure 1 and 2 are, as I read the information, based on stations in just 50 cities in the US, while Figure 3 is country-wide using the entire co-op network, so even though the data in earlier years is sparser there is adequate coverage for robust country-wide estimates.

Reply to  Weekly_rise
May 26, 2021 1:13 pm

Weekly-rise,
I can only gently offer to you this wise advice that has been around for many decades now:
“When you find you are digging yourself deeper and deeper into a hole, the first rule is to stop digging!”

Reply to  Weekly_rise
May 26, 2021 6:12 pm

The EPA website describes”

Baseless rationale. Ditching, modifying, changing, deleting data, especially Federally collected official data is not only unprofessional it is illegal.

That you readily accept vague waffle words as meaning something demonstrates your own bias, not a legitimate rationale.

“Additionally, Figure 1 and 2 are, as I read the information, based on stations in just 50 cities”

Urban heavily UHI affected stations, including airport locations… Is it possible to introduce more bias?

Weekly_rise
Reply to  ATheoK
May 27, 2021 5:19 am

Baseless rationale. Ditching, modifying, changing, deleting data, especially Federally collected official data is not only unprofessional it is illegal.

Data has not been ditched, modified, changed, or deleted. So there is no concern on that front.

Urban heavily UHI affected stations, including airport locations… Is it possible to introduce more bias?

Are you proposing that urbanization cannot have potential negative health impacts associated with high/low temperature events? I think it’s pretty much common sense that heat waves are worse in cities.

Geoff Sherrington
Reply to  Weekly_rise
May 27, 2021 4:12 am

WR
Would you like to comment on this Australian study?
http://www.geoffstuff.com/capcent.xlsx

This shows Century days going back to the 1850s in Australian cqpital cities.
Note this strange effect. The most and hottest heat waves are in Melbourne, not 500 km north in Sydney, nor another 700km north in Brisbane, north being closer to the Equator. It means that the ambient weather in these places is not a good indicator of hot weather, which originates in central Australia and typically moves 1500 km S-E at times of heat waves. Therefore, if you read a paper about heat waves that does not consider hot winds blowing in from afar, you will not get a very relevant story. Geoff S.

Weekly_rise
Reply to  Geoff Sherrington
May 27, 2021 5:20 am

Happy to take a look if you can provide a citation to the paper – I am not comfortable downloading an unknown .xlsx file to my computer.

Geoff Sherrington
Reply to  Weekly_rise
May 27, 2021 4:17 pm

WR
What a load of nonsense! Hit the button and learn something useful.
What ‘paper’? Do you think that experienced scientists should submit for publication what is little more than a listing of public data, rearranged to emphasize some features, with little more skill input than adding up and taking away? If so, why do you have an interest in degrading the quality of science by taking it down to comic book level? Geoff S

Richard Page
Reply to  Weekly_rise
May 26, 2021 8:23 am

“So it is both clearly documented and well justified.” Absolute tosh and rubbish – dig deeper and do some due diligence in your research before coming out with a line like that please. If you did, you would discover that the only organisation that considers night time hot temperatures more dangerous than daytime ones is the EPA – all articles and reports that use these terms originate with EPA reports. Then when you dig into the EPA reports themselves, you find that even they cannot support your premise; the closest they get to it is this – night time hot temperatures can be as dangerous as day time hot temperatures to those that cannot find somewhere to cool down, such as the homeless. Do not blindly follow the lies – due diligence in research or expect to be called out.

Reply to  Weekly_rise
May 26, 2021 3:37 pm

“Also the website does indicate pretty clearly that it is using daily minimum”
It does. We’ve seen pretty random shots at the EPA lately. First we had Francis Menton, erasing the heading on an EPA graph of USA48, then comparing it with a global plot and saying that the difference was EPA lies. Then a few days ago we had Larry Hamlin “EPA “Disappears” the 1930s Drought and Heat Wave Climate Data” when the “disappeared graphs were still there, perfectly visible. And now a tangled claim that they are misleading about using minimum temperatures (“EPA deception” again), when it is clearly stated.

paul courtney
Reply to  Nick Stokes
May 26, 2021 7:02 pm

Mr. Stokes: As you have noted, the graph was not disappeared. It was downgraded, but it’s still reliable enough to keep that data from the thirties on that thumbnail, right? We know those folks will disappear stuff (like wildfires) if the data is not reliable, and you’re good with that. Here, though, the data is good enough to keep that old graph. So we wonder why that old data is somehow not good enough to include in the now featured graphs, which begin in the sixties. Don’t you wonder why they would remove that data (from the thirties) from the new graphs by starting the new graphs in the sixties? It almost looks like the new graphs are effectively hiding the “non-conforming” data. Can we call it Nature Trick II? Are you good with that?

Reply to  paul courtney
May 26, 2021 9:45 pm

“Don’t you wonder why they would remove that data (from the thirties) from the new graphs…”
You aren’t reading very carefully. Fig 1 is for 50 cities; Fig 3 is for US generally. It is different data; they didn’t just cut Fig 3 to get Fig 1. For those 50 locations, they may not have had adequate data in the thirties. 

But that is how that scattershot EPA-bashing goes. EPA has deleted data! (chorus Goebbels, Soviet etc). Oh, it’s still there? But why is it Fig 3 instead of Fig 1. (Orwell, Biden etc). And now another “EPA deception” that wasn’t there. And it’s still “Welcome to the Biden era of climate science distortion, deception and dishonesty”.

Reply to  Nick Stokes
May 27, 2021 5:16 am

Personally, I would use the graph with the longest data set as my leading graph, rather than choose a shorter data set as my headline-grabber. Surely you agree Nick that more data is better than fewer data?

paul courtney
Reply to  Nick Stokes
May 27, 2021 8:46 am

Mr. Stokes: Let’s review. The Agency had and still has the old graph, so they have the data from the thirties. That data must be valid enough to keep. They create a new fig. 1 that excludes that data (as you say, different data). Why use “different data” to create graphs that show a trend, when the data that is (you now admit purposely) excluded would show a different trend? An EPA deception proven in the article, which you try to obscure. Mr. Hamlin has shown the deception, although he was mistaken about the fig. 3 being removed entirely. He is not mistaken that the featured graph is showing a deceptive trend by cherry-picking, something you complain about elsewhere. Not here, though. Interesting.

Tom Abbott
Reply to  paul courtney
May 27, 2021 4:08 am

“Don’t you wonder why they would remove that data (from the thirties) from the new graphs by starting the new graphs in the sixties? It almost looks like the new graphs are effectively hiding the “non-conforming” data.”

That’s what it looks like to me.

The graph that shows the 1930’s as the most prominent decade should be the first graph you see when you go to the EPA website, if it were an honest website.

But they hide it. What they are trying to hide is the truth. Par for the course for the Democrats. The truth usually destroys any case they are trying to make, so naturally, they try to hide the truth as much as possible.

This is “the Science” radical Democrat style.

Reply to  Bruce Cobb
May 26, 2021 11:58 am

If the minimums are rising and the maximums are not, isnt it possible the relative humidity (amount of water in the air) has increased over the same period. Since water vapor is a greenhouse gas, far more powerful that CO2 in that respect, perhaps the models are biased towards the wrong greenhouse gas.

anyone recall that joke survey to get humans to ban dihydrogen monoxide? Sorry, i shouldn’t give them ideas.

Bindidon
Reply to  Bruce Cobb
May 26, 2021 4:03 pm

Oh how beautiful!

Some get upvoted who said something, and some get downvoted who had something to say.

I LOVE that.

J.-P. D.

AlexBerlin
Reply to  Weekly_rise
May 26, 2021 7:34 am

Errrr…. maybe because, in terms of absolute temperature, the minimums are rather harmless, while it is the scorching maximums that impact people and wildlife? What a funny question!

OBVIOUSLY the HOT parts of a heat wave are what makes it noteworthy and potentially dangerous. That’s the very definiting of the term HEAT wave. “Higher lows” usually mean less amplitude in the day/night change of temperature and often translate into more temperate weather rather than into looming danger. A period with above-average daily lows combined with average or even below-average daily highs would not even qualify as a heat wave!

Weekly_rise
Reply to  AlexBerlin
May 26, 2021 7:40 am

See my comment above. According to the EPA website:

The most serious health impacts of a heat wave are often associated with high temperatures at night, which is usually the daily minimum.5 The human body needs to cool off at night, especially after a hot day. If the air stays too warm at night, the body faces extra strain as the heart pumps harder to try to regulate body temperature.

Reply to  Weekly_rise
May 26, 2021 8:00 am

And yet most people are indoors at night, in the shade and often with fans.

Also, I dispute the idea that “the body faces extra strain as the heart pumps harder to try to regulate body temperature” while asleep.

Weekly_rise
Reply to  M Courtney
May 26, 2021 8:12 am

The paragraph cites an EPA assessment of temperature related deaths and illness, which in turn cites the following research papers in support of the claim that night time temperatures are more closely linked to mortality than daytime:

Temperature, temperature extremes, and mortality: a study of acclimatisation and effect modification in 50 US cities

Comparing exposure metrics for classifying ‘dangerous heat’ in heat wave and health warning systems
Just doing quick Googling I found this paper:

Effect of night-time temperatures on cause and age-specific mortality in London
Which would also seem to endorse that view.

Richard Page
Reply to  Weekly_rise
May 26, 2021 8:42 am

Which does not support your premise that night time hot temperatures are more dangerous than hot daytime temperatures. The only premise that is drawn is that that maximum hot daytime temperatures are dangerous and that IF those temperatures persist into the nightime, then it may increase the risk in some people. The risk is in high daytime temperatures and in persistent ongoing high temperatures where I would contend that it is the stress of hot temperatures over a longer period of time that was a critical factor. Using minimum temperatures as a metric CANNOT be supported by the data.

Weekly_rise
Reply to  Richard Page
May 26, 2021 9:45 am

I don’t think the implication is that night time heat is per se more dangerous than daytime heat, but that the combination of hot days and nights that remain hot are the deadliest days, and using the daytime minimum captures this (daytime max will not capture days where the daytime temperature was high but the air cooled quickly at night).

Reply to  Weekly_rise
May 26, 2021 8:46 am

Read your first paper. It says nothing about day or night (did you bother to read it yourself?.
However it does say this:

Our findings strongly suggest that any assessment of the public health impact of global warming should take into account the ability of populations to adapt. Central heating prevalence may be a key to cold adaptation. Heat effects show more regional variation in the US, and likely elsewhere in the world.

Obviously, aircon and central heating work better indoors. And people are more likely to be indoors at night.

Your second link is just an abstract. Don’t know what it says about day and night as that’s not in the abstract but it does give its conclusion. That seems to be that this paper knows better than the existing papers how to tell what a hot day is. Maybe it does. Bet the other papers disagree though.
Highlights

► Our multi-level hybrid clustering method is a new way to identify hot days. ► We compared this method to other triggers used in heat and health warning systems. ► The days identified as ‘hot’ differed moderately or greatly among trigger methods. ► Our new method is relevant for prevention programs and pollutant mixture research.

Your third link (what a lot of rubbish you’ve posted so far. I hope you will apologise) finally addresses the question. Of course it is related to UHI not AGW but at least we are talking about day and night.

The study also demonstrated that warm nights preceded by a hot day have the greatest health impacts, indicating that nighttime temperatures are an important consideration when developing heat–health warning systems.

However, adaptation still needs to be considered. Indoors can have fans and aircon.
So, no. Night time temperatures are not more important than the day. And your best article (the London survey) says it is only an additional factor.

The real problem is poor housing

Weekly_rise
Reply to  M Courtney
May 26, 2021 9:41 am

To clarify for you, the first two papers are not “mine,” they are simply the citations given in the EPA assessment. Both papers adopt the methodology of using the daily minimum to define extreme hot days, so I assume the EPA is indicating that they have followed this methodology. This appears to be a standard/common approach.

Reply to  Weekly_rise
May 26, 2021 10:40 am

My apologies if I mistook what you posted as being what you thought was relevant.
However, the abstract of the second link say it is not a standard/common approach.
It might be a good approach. I’m not buying the paper to find out. But you really ought to at least read what you are linking to.

Reply to  M Courtney
May 26, 2021 1:33 pm

Indoors can have fans and aircon.

Yes, indeed. That is, UNTIL the high priests of Weekly_rise’s Church force all of the peasants into energy poverty.

Clyde Spencer
Reply to  Weekly_rise
May 26, 2021 8:55 pm

The paragraph cites an EPA assessment

It reads more like a rationalization or excuse.

Richard Page
Reply to  Weekly_rise
May 26, 2021 8:26 am

See my post on this. You are peddling misinformation and lies. Either research what you are writing about or just don’t bother. This is very easy to disprove.

Jeffery P
Reply to  Weekly_rise
May 26, 2021 8:48 am

Good thing we have air conditioning! Maybe the EPA should have updated their assessment to take that into account. When I grew up, you were rich if you had anything more than a single wall-unit for air conditioning. If you had central air, people probably drove by your house just to look at it.

The facts show more people die in cold snaps, on average, than heat waves.

Weekly_rise
Reply to  Jeffery P
May 26, 2021 8:55 am

The facts show more people die in cold snaps, on average, than heat waves.

And yet we have heating in homes…

Reply to  Weekly_rise
May 26, 2021 9:19 am

Are you really suggesting that the heat is expected to be as deadly as the cold?

meab
Reply to  Weekly_rise
May 26, 2021 11:32 am

We also have elderly people who can’t afford to run their furnaces day and night, poor people who can’t afford to fix a broken furnace, natural gas supplies that freeze up in severe winter conditions (Texas just this last February), and {revelation to the hard-of-thinking} people who die outdoors in the winter.

Reply to  Weekly_rise
May 27, 2021 5:22 am

Here’s a little experiment for you:
Stand naked in a desert for 3 hours and see how you feel, then stand naked at the South Pole for 3 hours and see how you feel.
I’d say I’d wait for the outcome, but you’d be dead at the South Pole by then.

Reply to  AlexBerlin
May 26, 2021 8:04 am

Try telling that to someone in the arctic circle…its the -50°C overnight lows that wreck materials kill people and stop machinery working, that are significant

Reply to  Weekly_rise
May 26, 2021 7:39 am

At the very simplest… heat waves are only a problem because of heat stress. They damage crops and cause illnesses.
That’s at the extremes, obviously.

Now… technical bit here, the minimum temperature is not the extreme in a heatwave.
If it were it would be called a coldwave.

In fact we can reasonably speculate that the minimum temperature is probably most influenced by deliberate human intervention such as the UHI effect. It rises from the low extreme because that is desirable.

Also, cutting off the 1930 is deliberately misleading. It’s a statistical no-no called cherry-picking.

PS. As numbers are not your forte may I suggest a more artistic means of studying the question. I recommend reading “The Grapes of Wrath” by John Steinbeck.

Weekly_rise
Reply to  M Courtney
May 26, 2021 8:38 am

Now… technical bit here, the minimum temperature is not the extreme in a heatwave.

A high daily minimum would reflect hot nighttime temperatures, which can certainly be a health risk.

Also, cutting off the 1930 is deliberately misleading. It’s a statistical no-no called cherry-picking.

The EPA article indicates that the data coverage becomes sparser as you go back for the stations used in Figures 1 and 2, since there are only 50 metro stations represented. The data in Figure 3, which uses the entire station network, extends back into the 30s.

Reply to  Weekly_rise
May 26, 2021 9:25 am

I’ve debunked your “Warmer coldest temperatures are more extreme than warmer hottest temperatures” above. It wasn’t hard.

So now let us return to the cherry-picking of data.
Either we have not enough data to make any policies on.
Or we do have enough data… data that used to be published prominently on the website and is still published in a thumbnail… but they chose to downplay it.

Either it’s good data or it’s bad data.
Now, seriously, go read The Grapes of Wrath and maybe you will find out which it is.

Note: The 1930s is not pre-history. We do not need to manufacture proxies to find out what happened.

Weekly_rise
Reply to  M Courtney
May 26, 2021 9:50 am

I think you are confused about what’s shown on the EPA website. Figures 1 and 2 (which only go back to 1961) show data for 50 stations in metropolitan areas, and are adapted from Habeeb et al. (2015). Figure 3 (it is not just a thumbnail, click the image and it appears full-size in the image box at the top of the page, just like all the other figures) shows data from the entire NWS co-op network, so represents a much larger sample size. Fewer stations in the early years will not be nearly as significant for the trends in figure 3 as for the trends in figures 1 and 2.

It’s not a question of good or bad data, it’s a question of whether there is enough data available to be confident that the trend reflects the population.

Forrest Gardener
Reply to  Weekly_rise
May 26, 2021 10:39 pm

Speaking as someone who is out of his league, you are way out of your league.

Lrp
Reply to  Weekly_rise
May 27, 2021 11:27 am

You are doing a bad impersonation of Nick Stokes at sophistry. Evidence is evidence and that is enough.

Tom Abbott
Reply to  M Courtney
May 27, 2021 4:31 am

“Note: The 1930s is not pre-history. We do not need to manufacture proxies to find out what happened.”

The alarmists want us to think the last century is ancient history and people couldn’t possibly read a thermometer properly in such an unsophisticated, crude time.

That way, they can try to dismiss all the temperature readings that put the lie to the Human-caused Climate Change narrative, where it was just as warm in the 1930’s as it is today, although there is much more CO2 in the atmosphere today than then.

So CO2 does not have much influence on temperatures if there is more of it in the atmosphere today but it’s not any warmer than in the 1930’s.

The alarmists don’t want anyone thinking that way. So they lie and distort the facts and history. Like they are doing now at the EPA.

Nothing ever disappears on the internet, at least so far, so that, imo, is why the EPA doesn’t just disappear altogether the EPA graph showing the 1930’s as the most significant decade, and instead they downgrade it to a thumbnail on the page.

Yes, the internet, and private citizens have a lot of information that the alarmists would like to erase from history, but they can’t get to it yet. It won’t stop them from continuing to try to distort history to promote their cause.

Lies are all they have.

Clyde Spencer
Reply to  Weekly_rise
May 26, 2021 9:04 pm

A high daily minimum would reflect hot nighttime temperatures, which can certainly be a health risk.

When I lived in Phoenix in the 1950s, it often got uncomfortably cool at night and early morning. Now days, the Summer nights are almost always quite comfortable outdoors.

WR2
Reply to  Weekly_rise
May 26, 2021 11:00 am

Higher minimums are primarily a result of UHI and siting issues. Nobody is dying from higher minimums. Your BS detector is obviously malfunctioning, it should be obvious to any sane person why they chose that metric: because it showed the highest trend.

Tom Abbott
Reply to  WR2
May 27, 2021 4:34 am

And is why they started it in the 1960’s.

Reply to  Weekly_rise
May 26, 2021 8:00 pm

Because heatwaves are about the hottest part of the day, not the cool of the night. Using a decline in cooler nights as an indicator of hot days is clearly intentionally misleading.

Weekly_rise
Reply to  Andy Pattullo
May 27, 2021 9:30 am

Heat waves involve both hot daytime temperatures and potentially extreme heat at night time. Using the daily minimum captures both (a hot night must necessarily have been preceded by a hot day, because it is the daytime when temperatures warm).

Lrp
Reply to  Weekly_rise
May 27, 2021 11:36 am

Not necessarily. If the highest temperatures have not increased, It’s a reflection of increased thermal mass

Tom Abbott
Reply to  Weekly_rise
May 27, 2021 3:52 am

“It’s unclear to me how using the minimum daily temperatures in calculating heat wave numbers would be misleading.”

I think starting the chart in the 1960’s is what is misleading.

Weekly_rise
Reply to  Tom Abbott
May 27, 2021 5:58 am

There are two charts that start in the 1960s showing data for 50 cities, and one chart that starts in the 1890s showing data for the entire nation. The reason for starting figures 1 and 2 in the 1960s is clearly explained on the EPA website (lack of adequate data coverage for the 50 cities being shown). There is nothing misleading here.

Bindidon
Reply to  Weekly_rise
May 27, 2021 1:52 pm

Weekly_rise

” It’s unclear to me how using the minimum daily temperatures in calculating heat wave numbers would be misleading. ”

It is not misleading at all.

As I replied to Tom Abbott upthread:

At that time, I did the same for France, to look at what happened there in 2003.The heat wave in 2003 has shown the same as 1934/36 for CONUS: highest number of maxima observations PLUS highest number of highest minima observations. ”

No idea how all these people manage to discredit your opinion, which is ABSOLUTELY correct.

I have read many articles in French newspapers concerning the 2003 heat wave, printing the opinion of many doctors there, namely that the heat at night following the day heat is far more destructive than the day heat alone, especially for very aged persons.

It seems to me that none of the commenters contradicting you did ever live in a cheap two-room flat without clim. They thus all don’t know what they are talking about.

In July 2003, I was in the Provence and spent there a week in such a flat. It was terrifying. And I was only 50!

J.-P. D.

Tom Abbott
Reply to  Bindidon
May 28, 2021 4:58 am

“In July 2003, I was in the Provence and spent there a week in such a flat. It was terrifying. And I was only 50!”

Persistent high-pressure systems will do that to some people.

I remember a time when I was a boy in Oklahoma and we had a water cooler as a cooling device, and it works just fine up to about 100 degrees F, but above that, it doesn’t do you any good at all because it is just blowing hot air.

Cheshire Red
May 26, 2021 7:36 am

He who hides something has something to hide.

Roger
May 26, 2021 8:16 am

Keep the climate change lie going, whatever the cost. And don’t worry about your standing because of your lies. The MSM and your compatriots have your back. Our only qualifier is for you to never tell the truth, or we’ll pull your funding. Just keep lying because you’ll be well funded, and there will come a time when the lie takes on a life of its own. At that point, the lie will become truth and will be self-sustaining. We can begin dismantling the US economy for valid, truthful reasons and no one will object.

So, for the sake of God and truth, just keep lying.

Meab
May 26, 2021 8:37 am

By using only temperatures measured in 50 large cities the EPA is biasing temperatures high because of the Urban Heat Island effect, and maximizing the apparent change over time as cities have grown. This is clearly dishonest.

Duane
May 26, 2021 8:42 am

To quote the warmists:

We’ve got to hide the decline

Tom Abbott
Reply to  Duane
May 27, 2021 4:36 am

“What about that 1940’s blip”?

dk_
May 26, 2021 9:07 am

This comes immediately following the press release wherein NASA grossly “misrepresents the actual science and defeats its stated” goals for space exploration and exploitation. Its like a trend or something.

May 26, 2021 10:03 am

Aren’t they really shooting their feet here…
They have re-hashed the data to make it appear they were/are more heatwaves.
(We’ll ignore whatever was deemed wrong with the previous method coz it’ll only become an interminable and ugly argument)

Now then: Heatwaves are supposed the cause fatalities.
Thus, have they modified the number of fatalities to suit the new number of heatwaves? How many d3ath certificates have they re-written?
In all seriousness, they cannot can they. The number of folks who died is the number of folks who died. period

So, by taking this new (increased number/strength/heatness) heatwave data at face-value and correlating it with fatalities, couldn’t someone/anyone demonstrate that heatwaves are a whole bunch less dangerous than they were previously made out to be….

Jon R
May 26, 2021 10:33 am

Sooner or later the church of deceit will be met with wrath.

Al Miller
May 26, 2021 11:25 am

Hmm, looks like the same old deception, lies and cherry picking that has been going on since the “Ice Age Coming Fast” that I recall so well from the late ’70s.
I am heartened to hear so many of my acquaintances who are by no means activists refusing to watch or listen to the media anymore due to all the lies and propaganda. Please note the word “news” is intentionally omitted from media.

Rod evans
May 26, 2021 11:37 am

Does the EPA still classify CO2 as a pollutant?
If they do, why does anyone pay any attention to their other misunderstandings of life’s fundamentals

Chris Hanley
May 26, 2021 2:54 pm

What is a heatwave?
A heatwave is an extended period of hot weather relative to the expected conditions of the area at that time of year, which may be accompanied by high humidity.
A UK heatwave threshold is met when a location records a period of at least three consecutive days with daily maximum temperatures meeting or exceeding the heatwave temperature threshold.
The threshold temperatures have been calculated using the 1981-2010 climatology of daily maximum temperature at the mid-point of the meteorological summer.
https://www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/temperature/heatwave

Tom Abbott
Reply to  Chris Hanley
May 27, 2021 4:44 am

In Oklahoma and surrounding States, we have had extremely hot weather that has lasted for weeks, months, and years.

This extremely hot weather would not necessarily qualify as a “heatwave” since the extreme heat comes and goes, but it sticks around and does not cool off like it normally would, and in a couple of cases has lasted for more than one year, which would mean that over the winter it stays unusually warm and dry and then when spring rolls around the extreme heat comes back with a vengeance and stays until October.

That was the case around 2010-2011, around here. It was hot that whole period of time. Happily, we haven’t experienced anything like that since that time.

Geoff Sherrington
May 27, 2021 1:55 am

Australian heat waves are depicted by The Establishment as increasing in frequency, severity and duration. Years ago I took the 6 State capitals as examples because they had some of the longest weather records and because most of Australia lived there. Important for planning hospitals for heat wave victims, more relevant than examples from the Central Desert with no hospitals. Sadly, the capitals have probable UHI effects that make analyses seem worse than real.
Here is some of the analysis I did.
http://www.geoffstuff.com/heatwave_capitals.xlsx
One main conclusion is that heat wave analysis can be manipulated by making up a new definition for a heat wave and using it to your advantage. I did not do that. I simply took the strongest 40 heat waves, only one each year, of durations 1 day, 3 days, 5 days and 10 days.
Then I counted the number of days each year with Tmax above 100F. Not much room to fiddle this way.
Another major conclusion for heat wave analysis – data about the weather at a test location is far less important than the weather data at the region, often 1000 miles away – where hot cells form and get blown to the test site.
Geoff S

Paul Jenkinson
May 27, 2021 7:56 am

Anyone who has read this article and now knows what data has been ignored by the EPA to support their ongoing funding,and still claims the EPA paper is a legitimate scientific undertaking is making a fool of themselves.

June 1, 2021 12:31 am

Here’s the WayBack Machine link to the original Heat Wave Index chart.
comment image

Reply to  Steve Case
June 1, 2021 12:36 am

Let’s try again to put up the way back machine