A heatwave in the UK in March? Nope
Various online newspapers in the UK ran articles about the ‘heatwave’ currently gripping the country yesterday. But was it actually a heatwave? What is a heatwave?
The Met Office definition of a heatwave is ‘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 varies by UK county, see the UK temperature threshold map below.’
The Met Office map:
We can see the threshold is higher in the south of the UK, with London having the highest threshold, because of the Urban Heat Island Effect, which is greater in bigger cities, and because it is 600 miles further south than Scotland.
It should be noted the Met Office says a heatwave is defined as a minimum of three days above the threshold, and we had one day, possibly two, so by that definition, there was no heatwave, but the climate alarmists will of course jump on the bandwagon and say it was.
The maximum temperature recorded yesterday (March 30th) was, according to the Daily Mail ‘Kew Gardens in South West London’ which recorded 76.1F (24.5C). Kew gardens is in the middle of London, so that temperature will have been increased by the Urban Heat Island Effect, probably to the tune of two or even three degrees.
The average March temperature for the UK, according to the Met Office, is 50F or 10C, so yesterday was significantly warmer than is usual for March.
However, some news articles accurately reported this as the second warmest March since 1968, which means 1968 was warmer. In fact, according to the Met Office, March 1968 recorded a high of 78.1F (25.6C), set at Mepal in Cambridgeshire. Some articles mentioned temperatures reaching similar across southern and eastern areas, but few details of where were provided.
Therefore, it has taken 53 years for us to see the same March temperature as 1968.
So much for global warming.
The Met Office website explains what causes heatwaves thus:
‘Heatwaves are most common in summer when high pressure develops across an area. High pressure systems are slow moving and can persist over an area for a prolonged period of time, such as days or weeks. They can occur in the UK due to the location of the jet stream, which is usually to the north of the UK in the summer. This can allow high pressure to develop over the UK resulting in persistent dry and settled weather.’
It then goes on to say what may have caused this unusual temperature yesterday:
‘It is 30 times more likely to occur now than before the industrial revolution because of the higher concentration of carbon dioxide (a greenhouse gas) in the atmosphere. As greenhouse gas concentrations increase heatwaves of similar intensity are projected to become even more frequent, perhaps occurring as regularly as every other year by the 2050s. The Earth’s surface temperature has risen by 1 °C since the pre-industrial period (1850-1900) and UK temperatures have risen by a similar amount.’
Being of the Slayer camp, I totally reject any mention of ‘greenhouse gases’. All the ice cores from both Greenland and Antarctica show temperature changing first, followed at least 800 years later by a change in CO2. Therefore, CO2 cannot drive temperature. Temperature drives CO2.
The Central England Temperature Record is the longest continuously-monitored dataset in the world. It began in 1659. It shows a temperature rise of about 1.2C over the last 360 years, as seen below. Hardly catastrophic.
The Met Office website also says ‘Summer 2018 was the equal-second warmest summer in a UK series from 1884 for mean maximum temperature (shared with 1995) with summer 1976 hottest.’
So according to this, the three hottest summers in the UK were 1976, 1995 and 2018, with 1976 the hottest. That is 45 years ago.
It then goes on to say: ‘In August 2003, the UK experienced heatwave conditions lasting 10 days and resulting in 2,000 deaths. During this heatwave, a record maximum temperature of 38.5 °C was recorded at Faversham in Kent. In July 2006, similar conditions occurred breaking records and resulting in the warmest month on record in the UK. In the summer of 2019, the 2003 maximum temperature record was broken at Cambridge University Botanic Garden on 25 July, with 38.7 °C.’
A record broken….by 0.2 of a degree.
In 2018, the Global Warming Policy Foundation published this temperature graph, showing UK average annual temperatures between 1910 and 2018.
It clearly shows that for 80 years the average UK temperature remained constant, then rose between 1990 and 2005, before levelling off and even falling slightly.
The weather forecast for the next few days is for much cooler temperatures, to around 52F / 11C by Good Friday, with snow possible in North Wales!
Two unusually hot days a heatwave doth not make.
I wonder if calling a heatwave after just three days is deliberate, to make them appear more common. I would have thought it should be a minimum of a week; seven days.
The Met Office website can be seen here: metoffice.gov.uk
The Daily Mail article is here: dailymail.co.uk
About the author: Andy Rowlands is a university graduate in space science and British Principia Scientific International researcher, writer and editor who co-edited the new climate science book, ‘The Sky Dragon Slayers: Victory Lap‘
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Hephaestus
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“The Central England Temperature Record is the longest continuously-monitored dataset in the world. It began in 1659. It shows a temperature rise of about 1.2C over the last 360 years, as seen below. Hardly catastrophic.”
That’s almost half-a-percent hotter! Real scary! Ring the alarm bells!
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Jerry Krause
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Hi Andy and hopefully PSI Readers,
The first three paragraphs were great. It is essential that we accurate define the words we commonly use. However, the fourth paragraphs also begins great because you are explaining the title of your article. By definition there were no heatwaves in the UK in Match. So, why did you add “but the climate alarmists will of course jump on the bandwagon and say it was.”
Your first figure was great and factual. But the next two had significant problems. You might ask: What were their problems? One problem was that after accurately defining what a heatwave by definition was, your ‘graph’ were of average annual temperatures. But even the average annual temperatures were not plotted; but deviations from the average of annual yearly averaged temperatures averaged over mamy years of average annual temperatures.
And When I study your second figure, I have to ask who averaged these average annual temperatures from 1669 to 2020??? For there are far more years of far lower temperature averages than there are for years when the average annual temperatures were above the “average’ of the average annual temperatures the many years between 1669 and 2020.
Andy, I really would like to read your explanation for this longest measured temperature record known to exist as seen in your second figure.
Have a good day, Jerry
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MattH
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Some of the averaging is pretty average!
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MattH
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Hi Andy and hopeful PSI readers.
I just checked out the global Mean Surface Level Pressure map and it looks to me the whole of the British Isles is currently being subjected to anomalous miserable cold with the wind stream coming strait off the arctic ocean.
Pray for a heatwave. I presume that cold is a killer.
Wrap up warm. Matt
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