CET Daily Temperatures
By Paul Homewood
https://www.metoffice.gov.uk/hadobs/hadcet/cet_info_max2023.html
I want to focus on the end of year CET graph, which gives the lie to the extreme temperature myth often bandied around.
The graph plots daily max CET temperatures, against the background of the percentiles of the 1961-90 climatology. The Met Office should of course be using 1991-2020 as the baseline, so the climatology should be shifted upwards by a half a degree or so. But we’ll leave that aside.
We can legitimately regard anything between the 5% and 95% bands as being “weather”. Only days outside this might be regarded as “extreme”. (I would actually argue anything outside 1% and 99%).
We see that apart from a handful of days, every day was within that “normal weather” band.
In a year there will be 36 days outside of that band on average. The Met Office do not supply the data for these percentiles to enable the number of days to be calculated, but this year it does not look to be excessive in terms of that average.
Moreover, although there were a few days in September which set record highs for that particularly day, none were records for the month as a whole. The highest temperature last September was 28.9C, but the record for September stands at 31.5C in 1906:
Of course most of the year had temperatures above the average. But we have a wide range of weather in Britain. We can have mild, wet winters, and cold, snowy ones; we can have cool, wet summers and sunny hot ones. But these are weather events, not climate, and they are dependent on weather patterns, the jet stream and so on.
A predominance of warmer weather is not climate change.
Comments are closed.
NOT A LOT OF PEOPLE KNOW THAT 
“The Met Office should of course be using 1991-2020 ”
The 30-year frame was established by the World Meteorology Organization (WMO) in 1935 — before computers — and selected because it was thought an adult would relate to weather data during their early years. Also, because there were no computers and digital information, more frequent calculations would be a burden.
There is no reason with the current state of digital everything that a “base period” should not be updated on a yearly basis. The CET has a very long run not comparable elsewhere. Maybe 1960 could work as a start year.
I suspect the 1961-1990 “climatology” is used because it makes the AGW narrative work better. A plague o’ all their houses!
Hi JH,
I didn’t know that about the 30 year time frame.
Learning has taken place!
Thanks!
I understand your point John, but would hesitate to institute it. Once you allow agenda driven organisations like the Met Office to annually adjust baselines and reference points you’ll soon find all manner of corrupt manipulations to push their propaganda. Dont open a door that will let them corrupt the data like the Aussie BoM and USA Goddard centre and NAOA and others have been doing.
Why does the Met office use CET which I would argue has a serious UHI effect given that England is the most densely populated country in Europe having now overtaken Netherlands (we can leave out eg Monaco)? Since we live in the UK why not use the UK figure? Hmm, is it because the temp trends are much less dramatic?
Unfortunately the UK set includes the likes of Heathrow, Kew Gardens, Cambridge etc!
Not to mention operational RAF airfields when flights of afterburning Typhoons are taking off!
I vote we only include temperatures from the tops of mountains and clifftops!! (like they do withn winds!)
Paul
I’d propose places like Altnaharra, Braemar, Eskdalemuir and Shap
I can’t think of many further south
You miss the point of the CET. It is supposed to represent a typical single point in the English Midlands. See my other response for Manley’s intentions and the continuation of the same spirit.
We see that apart from a handful of days, every day was within that “normal weather” band.
The null hypothesis of climate i.e. natural variation is still in the driving seat. Other ideas are on the fringes, like it or not.
“UK weather: 2023 was second warmest year on record, says Met Office”
https://www.bbc.co.uk/news/science-environment-67845671
I simply don’t believe them. Yes, June was hot (but not everywhere) as was a single week in September. Otherwise the year was average at best, with a lousy summer after June.
I wonder why the chart they use starts in 1940? I haven’t delved into the stats, but I know there were some scorching hot summers just before the first world war (and indeed, I believe 1939 was a pretty hot one too).
There is increasing public scepticism about this sort of thing. The highest rated comment (the BBC, perhaps foolishly from their point of view, allowed the public to add comment) is to this effect:
“I’m not sure about this chart…you’ve taken an average of a 50 year period and then missed 40yrs and then added the next 83 yrs on seperately.
Surely you either include every year after 1900 so you can see outliers or you take 50yr averages.
If you want to make a point then do it properly don’t make the chart fit your argument. Or at least don’t leave yourself open to this kind of comment”.
Esmee Stallard, not heard of her before. Why does the BBC need so many cut and paste artists?
She is one of the inner circle of Verify along with the likes of Marco Silva, Marinna Spring, Merlyn Thomas et alia. Ironically she is the only one with a vestige of a science qualification but all her output is similarly crap.
https://www.linkedin.com/in/esme-stallard-12266147/?originalSubdomain=uk
The Met Office is fiddling the figures, just as NOAA does in the US.
February 24, 2023 1500 Scientists Say ‘There Is No Climate Emergency’ – The Real Environment Movement Was Hijacked
Are you aware that 1500 of the world’s leading climate scientists and professionals in over 30 countries have signed a declaration that there is no climate emergency and have refuted the United Nations claims in relation to man-made climate change?
https://www.globalresearch.ca/1500-scientists-say-there-no-climate-emergency-real-environment-movement-hijacked/5809791
The UK met office lie monkeys won’t tell you they cooled the temp data as of Jan 2020. On the annual temps in the current warmest ten, 2018 was cooled 0.04c the others, 2014, 06, 11, 07, 17, & 03 all cooled 0.03c.
The warmest top 6 older years 1944, 49, 59, 1911, 1921 & 1938 all cooled on average 0.06c.1911 was cooled 0.17c, this is 5.6x the average of the more recent years.
There is no doubt it’s Mann made warming.
The whole scanario is fraud to scaremonger, it’s not science.
First link is pre jan 2020 data
https://www.metoffice.gov.uk/pub/data/weather/uk/climate/datasets_5km/Tmean/ranked/UK.txt
Link below is the cooled figures, ie current.
https://www.metoffice.gov.uk/pub/data/weather/uk/climate/datasets/Tmean/ranked/UK.txt
Climate zealots will argue [with no evidence] that the later data is based on 5km plots. But with no more met stations why should the data change overall ? But nobody can answer why the ‘adjustment’ cooled pre 1990 considerably more than 1990 to 2020, or why hotter years cooled more some months cooled 0.3c.
The blatant selective cooling is obviously an AGW bias deception to push the ,we are frying, narrative, yet 17x more die from cold in the UK than any heat ref The lancet.
Averages shouldn’t change if you “correct” random errors because the errors, if random, should cancel each other out. The MO cannot show systemic errors yet assumes thermometers ran warm far more often than they ran cold somehow.
And cooled pre 1990 by 3x that of 1990 to 2020, they also reduced the variation of sunshine hours to flatten the curve, & disconnect sun from temperature.
But, sun hours and mean temp correlate 100% long term, the last 5 years have been 10% warmer than the 100yr average with 10% more sunshine. Last 10 years 5% more than 40yr ave.
All ignored by the disengenuous UK Met Office.
The BoM (AUS) has been adjusting temps using ACORN data. Here was its first attempt.
http://www.bom.gov.au/climate/data/acorn-sat/documents/5-ACORN-SAT-TAF-TOR3.pdf.
They continue to adjust – for instance, 1914 is now +0.13C, down from 0.52C. Both 2001 and 2011 were both below the average mean temp – not any more. Man-made warming for sure.
Compare any one year with 30 other years.
In each of these years, there are 365 dates. Each one has a maximum temperature.
If all these 31 years follow a similar pattern, with random variations, each year should have 1/31 of the maximum temperature days, ie about 12/365 days.
2023 seems to have 12 maximum temperature days.
Therefore 2023 is entirely normal.
The current mark of the CET uses the average of three stations – Rothamsted, Pershore College and Stonyhurst. 0.2 deg C is currently subtracted as a UHI allowance. Many comments on this thread need to be retracted or adjusted accordingly.
Gordon Manley created the series from a weighted average of a small number of locations surrounding and within the English Midlands. He had already put together a long-term composite series for Lancashire and thought by incorporating a few southerly stations he could produce a series that could stand in for a typical site located somewhere in the centre of the country. He was no statistical hot shot (based on letters he wrote preserved in his archives) so did not appreciate that an average of n (albeit small n) data points would have lower variance than the individual data points entering the composite.
There has always been adjustments to the met stations contributing to the CET and I remember one leading to a bitter exchange in the 1970s between Manley and C Gordon Smith, the Oxford don and director of the Oxford Ratcliffe Camera observatory met site when the former decided to ditch it for a less urban Rothamsted. Oxford had been a long standing contributor extending right back to the early 1800s as well as being more obviously “central”.
Regarding location, of the current three, Pershore is sort of central but a bit off to the south-west, Rothamsted is well south and Stoneyhurst is a vestige of Manley’s Lancashire originals so well to the north. None are in the real “heartlands” (Meriden near Coventry being the actual geographical centre).
The basic philosophy of all those succeeding him – the Hadley Centre being the latest – has been to maintain the spirit of Manley’s intentions of a long-term temperature dataset that could be interpreted as being from an undisturbed single location somewhere in the middle of England. I simply don’t understand the opprobrium here to what is surely a laudable enterprise – a clear case of throwing the baby out with the bathwater.
Stonyhurst (Lancashire) is within about five miles of the geographical centre of the island of Britain.
Interesting and of course many ways to define a centroid. Personally I would go for an intellectual, scientific, cultural, historic, literary, and financial combined metric which would locate the centroid a little west of Watford:-)
Anyway, the way Manley himself put his best matching notional representative location was somewhere in “open rural surroundings in the lowlands of Staffordshire, Shropshire, North Warwickshire”. None of the three actual stations now contributing are close geographically speaking.
CET are absolute temperatures, they represent somewhere in their middle, but that position will have seasonal variations, and is difficult/impossible to maintain when one of the stations is switched. This is not good science, especially when a much better and simpler process is available: average temperature CHANGES, rather than absolute temperatures.
Manley was a simple geographer with a strong historical bent and did great service by pulling together material dating back to the 1600s that would give a fair assessment of the evolution of the weather in England. I say “weather” as there is a similar series he produced for rainfall.
I have spent time with his workings – they are held in archive boxes in Cambridge University library – with reams of number columns trying to bridge or stitch what is inevitably disjoint given the time span. Read his papers, available online, for more on the fascinating source material he worked with.
Your appeal for spatial average is met by other data sets which are often referred to here in “Not a lot of people know that” so I am surprised you are unaware. Were you even aware of the historical climatology aspect of CET?
I didn’t follow your issue with seasonal variation. They are a feature of weather data so have to be recognised. Manley worked with a monthly time step which is probably as much as could be reasonably managed in his day; those following him use a daily time step but not back to 17th century.
Temperature gradients across England vary with the season, hence the effective position of CET will move with the season.
I am unaware of any suitable long history of daily temperatures other than CET, probably why it is always cited here. Oxford has demonstrable UHI.
So, you’re saying the steepness of the slope of the north-south (for example) temperature gradient follows some sort of sinusoid. Maybe, but I can’t see how that invalidates an average of the three fixed points (which haven’t included Oxford for 50 years). The average is what it is, an average. It will be comparable to the average of the same three points subject to the usual provisos about real world field measurements. There isn’t an actual central england point whose lat long you can quote – it’s a purely notional entity whose imputed temperature value lies in its longevity.
Yes you can average 3 temperature records, but it does not have a simple physical interpretation, and it will have non-climatic jumps whenever one of the stations is changed.
Thankyou for the interesting information. Regarding Pershore, I have noted recently that the Met Office have quoted data (for whatever latest “record” is in vogue) from the former RAF Throckmorton station and not the college site.
Do you know of any genuine reason why the artificial airfield site (complete with tens of thousands of buried livestock from the Foot and Mouth slaughter) would be chosen over the College site so close by?
I don’t know the answer to your question, but more than happy to indulge in a spot of theorising. Maybe students couldn’t be trusted with a met enclosure (abusing the raingauge etc), or maybe the powers of darkness reckoned the heat generated by all those festering corpses would yield more favorable temperatures to fit the scam.
Paul, the problem with your analysis is that the data isn’t up to the task.
While it has been claimed to be a continuous series, in fact there are no less than seventeen! changes in the stations used to calculate the CET. That makes long-term comparisons … well, let me call them “problematic”.
Not sure if your site will take inline images, but here’s a try. It shows the timing of all of the splices.
w.
In fact the CET has been very carefully homogenised every time a station change has occurred. Only one change has occurred since the 1950s, when Stonehurst replaced Ringway in 2004. Prior to 1961 is of course irrelevant to this excercise.
See here: https://www.metoffice.gov.uk/hadobs/hadcet/Parker_etalIJOC1992_dailyCET.pdf
It may not be ideal, but it’s the best daily dataset the Met Office has got, if you don’t want UHI contanimated urban sites!
More importantly, I don’t believe that any of this affects the overall conclusions about “extreme temperatures”