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No Trends In Hot Days In May, Despite Met Office Misinformation

June 2, 2022

By Paul Homewood


 I posted on this a couple of weeks ago here.








Now we have the full numbers for this May, we can take a closer look at CET trends.

ECA&D has data up to 2020, but there have been no days of 25C or more, either this May or May last year. The top temperatures were 22.8C and 21.8C respectively.

There is clearly no upward trend in “Summer Days”, the 90th percentile or maximum daily temperatures:




Any attempt by the Met Office to persuade the public otherwise is reprehensible.


I noticed on checking that the current CET data did not tally with the above – 1947, for instance, only showed three days of 25C+, as opposed to four on ECA&Ds.

On reconciling the two, I see that all of the CET daily numbers are now moved back a day. So, the four days of ECA&Ds which recorded 25C were the 28th through 31st May. The official CET data now lists the same temperatures on 29th May through 1St June.

No doubt there is a sensible reason for this!

  1. Gerry, England permalink
    June 2, 2022 10:52 am

    It was a pretty cold end to May in my SE corner of England. There was one evening where I considered lighting the fire. Had the heating not been turned off on 1 May, there have been mornings when it would have come on. And to ensure my bread would rise, I had to put my breadmaker in the conservatory.

    • that man permalink
      June 2, 2022 12:35 pm

      Indeed, and it’s been/still is pretty chilly oop North here in Lancashire.

  2. Ben Vorlich permalink
    June 2, 2022 10:57 am

    The object is not for people to remember the actuality but the headlines of forecast hot days. Getting a hot day at an airport is a bonus as people tend not to remember the disappointment of a non-appearing hot spell then quoting the hottest day on a certain date for a number of years is all they need.

    • that man permalink
      June 2, 2022 12:32 pm

      Additionally, at Heathrow the thermometer is housed on a greensward adjacent to runways. Apart from solar gain retained by the hard surfaces, the heat generated by engines on full thrust at takeoff, and conversely on reverse thrust after landing, must be factored-in particularly in still-air/low wind speed conditions. Now consider the increase in air traffic over the years……

      • June 2, 2022 3:02 pm

        The main reasons that Heathrow gets a lot of records is probably more geography than jets. Factoring in latitude, distance from the sea, rainfall and sunshine, Heathrow is probably close to the optimum location for hot summer days.

      • MrGrimNasty permalink
        June 2, 2022 6:44 pm

        The jet thrust angle is a red herring, generally, there was one slightly suspicious incident. The main reason is the London conurbation and the site’s piles of concrete buildings, concrete and tarmac and short grass surfaces. I worked there doing business/systems analysis work on their financial systems in a past life, you’d get a sweat on in January before you’d even parked up, and the offices were full of portable air conditioners all summer.

      • that man permalink
        June 2, 2022 8:27 pm

        ….obviously the UHI effect is significant, but to dismiss the contributions of huge turbofans as a ‘red herring’ is nonsense. See for a well-reasoned analysis.

      • MrGrimNasty permalink
        June 2, 2022 10:36 pm

        It is nonsense, if jet engines were regularly causing spikes there would be dramatic rapid temperature deviations from other nearby hot sites all the time. There simply isn’t. There was ONE slightly suspicious record claim where it may have been an issue, but more likely just wind shift.

    • Ray Sanders permalink
      June 2, 2022 4:56 pm

      “The object is not for people to remember the actuality but the headlines of forecast hot days.” That is a very good point. I noticed how leading up to the Platinum Jubilee the weather forecasters had been very coy even to the extent that three days ago they were cautioning against the accuracy of forecasts “so far head”. Put another way, the actual Jubilee is a memorable date point and people would remember any inaccuracy of the forecast.

  3. woodburner0 permalink
    June 2, 2022 11:07 am

    Nothing precise, but I remember it being warmer in April than May, some of the time.

    • Phoenix44 permalink
      June 3, 2022 8:54 am

      Well the UAH global satellite anomaly was higher in April than May! Interesting given the hysteria about temperatures in India and Pakistan.

  4. Peter Yarnall permalink
    June 2, 2022 11:25 am

    Local weather blogger Oldham Weather,(@chadweather) reported that on Monday 30th May, the temperature failed to teach double figures all day. Still waiting for the BBC to claim, “Hottest May Evah!”

  5. cookers52 permalink
    June 2, 2022 11:28 am

    The poor quality of the Met Office analysis confirms that their science is corrupted by confirmation bias.
    However I wish the actual weather was corrupted by confirmation bias, as it has been quite cold.

  6. 2hmp permalink
    June 2, 2022 11:34 am

    I have long since ignored Met Office temperature and weather statements, not because they do not have the facts to hand, but because they politicise a left wing agenda

    • Peter Yarnall permalink
      June 2, 2022 1:14 pm

      I regularly use the Met Office, often when abroad. Their forecasts are very accurate. Whilst in Colorado last year, their daily forecasts were more accurate than the locals, much to the amusement of an acquaintance from New York!
      Sadly, their future projections bear absolutely no relation to their own recorded data.

  7. Jack Broughton permalink
    June 2, 2022 1:33 pm

    Ah well, I just heard that Justin Rowlatt is presenting some essential listening on radio 4 next week covering the imminent climate tipping points: must listen ….. maybe on someone else’s radio!

    • June 2, 2022 7:02 pm

      The yawnometer could reach *unprecedented* highs 🥱

  8. John189 permalink
    June 2, 2022 1:44 pm

    I recently posted elsewhere that I was surprised by a provisional CET positive anomaly of 1.9 Celsius for May 2022. The Met Office state that the anomaly is in relation to temperatures in 1961-90 “because this is the standard period period of reference for monitoring climate change” so this may well distort impressions of 2022 versus more recent years. That said, I am still surprised. It may have been an absence of very cold nights – it certainly isn’t due to the prevalence of very warm days – nothing like the 30 Celsius in NW Scotland in May 2012 or a week of widespread 24 Celsius or above in early May 1995. Furthermore, full tree leaf cover arrived on the borders of West and North Yorkshire only in the final week of May, the latest since (off the top of my head) 2010.

    • dave permalink
      June 2, 2022 6:18 pm

      The shtick about a standard period of reference is blather.

      Data is what data is. Drawing a horizontal line adds nothing to and subtracts nothing.from a graph.

      The World Meterological Office has its knickers in a twist. On the one hand it says 1991-2020 should be the standard period and on the other it says 1961-1990 should be used ‘for history.’ But to look back is always to gain historical perspective, is it not?
      Obviously, most of the WMO busy bees believe their real job is to advance the agenda.

    • Phoenix44 permalink
      June 3, 2022 8:59 am

      Without taking into account the variability around the mean, “anomaly” is meaningless. If we want to do something that resembles science, we should take as long a reference period as possible that is unaffected by climate change – say 1850 to 1900. If there’s a possibility that doesn’t fully encompass cycles, then adjust it – and explain the cycles! Then work out the distribution and describe differences from the mean properly using that distribution as the reference, not the mean. 2 or 2 SDs from the mean is not evidence of unusual weather.

  9. W Flood permalink
    June 2, 2022 2:18 pm

    This has been a cool May in S Scotland and I am very surprised at the 1.9 C anomaly.

    • Mark Hodgson permalink
      June 2, 2022 8:27 pm

      A cool May in NW Cumbria, too, with spring being delayed this year, so far as I am concerned. Many days, even late in May, saw top temperatures briefly touching 13C. Full leaf coverage on trees seems to have been achieved only in the last week or so. Ash trees were still bare until very recently.

    • Phoenix44 permalink
      June 3, 2022 9:01 am

      Is that min-max average or mean of the max? I suspect we have seen a continuation of above average mins rather than anything else.

  10. catweazle666 permalink
    June 2, 2022 4:57 pm

    “The UK average mean temperature for May has increased from 9.8°C to 10.6°C in 30 years (1961-1990 compared to 1991-2020).”


    Proportionally, an increase of 0.8°C from 9.8°C to 10.6°C looks like a lot in degrees Centigrade , but in Kelvin…

    • dave permalink
      June 2, 2022 6:35 pm

      Anyone who has absorbed and retained a good, basic science eduction automatically translates backwards and forwards between the Celsius and Absolute scales of temperature, without thinking twice. That is 2% of the population, then, who will see through silly, little, presentational tricks?

    • Phoenix44 permalink
      June 3, 2022 9:21 am

      The wholly false picture that presents is quite fradulent. These are averages of averages made to look like temperature increases whereas they are largely small changes in distributions. You can increase an average but have fewer or lower maximums and vice-versa. As with ever-contentious averages of girls and boys maths scores, the average can be identical but the distribution extremely different. The idea that having a few more days slightly above a mean from another arbitrary period is a problem is nonsense.

  11. Athelstan. permalink
    June 2, 2022 5:29 pm

    The civil servants at the Hadley centre are all set to global warming, it’s a group think response to government orders and it pays the mortgage. All other data sets are fixed to this simple fact and the modellers can shape anything they like, GIGO.

  12. europeanonion permalink
    June 2, 2022 6:18 pm

    You will have seen this of course

    As energy prices soar, behind the scenes, the UK government is planning to make it even harder to heat our homes. The government is threatening to force manufacturers of gas boilers to switch to making heat pumps. From 2024 onwards, Whitehall plans to levy severe fines on UK-based boiler manufacturers that fail to meet production targets for heat pumps, hitting them with a £5,000 penalty for each failure to deliver a unit.

    These Stalinist reprisals are the latest absurdity to result from the government’s hell-bent pursuit of Net Zero. To meet Net Zero carbon targets, the number of heat pumps installed in homes each year will have to multiply 12-fold over the next six years – from about 50,000 today to 600,000 by 2028. This would be a remarkable feat, given that to buy a heat pump and install a complete system currently costs between £8,000 and £28,000. Meanwhile, a working boiler system comes in at just £2,000 to £3,000.

    The idea for a £5,000 penalty came out of a consultation held by the Department for Business, Energy and Industrial Strategy (BEIS) with a convenient set of respondents – including 24 unnamed organisations and private individuals, 15 NGOs, eight heat-pump manufacturers and just seven makers of gas boilers. As BEIS puts it, having got the answer it wanted: ‘We share the view of the majority of respondents that payments or penalties for shortfalls against targets… will need to be sufficiently substantial to ensure that the policy will be effective and support a transformation in the market.’

    ‘Transformation’ is an apt choice of word. The switch from boilers to heat pumps is among the most fantastical of all the Net Zero aims. Aside from heat pumps being far more expensive than conventional boilers, the installation is far more expensive, too. To work properly, heat pumps also need up-to-date home insulation, new pipeworks and larger radiators – work which is extremely disruptive. Even after all that, heat pumps can take hours to heat your home and are incredibly noisy. Plus, the 15 per cent of the population who live in flats will have to opt for an ‘air source’ heat pump, as opposed to the standard ground-source model, which is more expensive to operate than a gas boiler.

    Of the 1.7million gas boilers that are installed each year in the UK, most are made domestically by firms like Vaillant, Worcester Bosch and Baxi. Yet the new government policy means their future (and that of their employees) is now uncertain.

    The policy also lays bare the undemocratic logic of Net Zero. The British people have never been asked if they want to trade in their trusted boilers for more expensive, less efficient heating systems.

    The heat-pump policy began life at the Committee on Climate Change (CCC), the unelected quango that advises the government on how to reduce carbon emissions. In 2020, the CCC called for 2.2million heat pumps to be installed in new homes and another 3.3million to be retrofitted in old ones by 2030 – seemingly without any regard to the cost or feasibility, not least given the lack of trained fitters.

    Whitehall later put forward the target of 600,000 installations per year by 2028. We won’t come close to achieving this based on current installation trends. Yet instead of rethinking the planned heat-pump revolution, BEIS is threatening more drastic measures to try to meet the target, including criminalising conventional boiler manufacturers.

    Alongside the stick, is the carrot. The UK government plans to spray money at the comfortable and the virtuous to encourage take-up. Through its newly announced £450million Boiler Upgrade Scheme, a modest 90,000 homeowners in England and Wales will now be able to get £5,000 off the costs of the unit and installation of an air-source heat pump, or £6,000 off the unit and installation costs of a ground-source heat pump.

    James Wouldhuysen

    (Why do we bother with personal finances when the government is hell bent on spending our money for us on state projects?)

    • that man permalink
      June 2, 2022 9:31 pm

      Very good, comprehensive post. Regarding “the 15 per cent of the population who live in flats…” the many fan units will have to be attached to the external walls or cladding, and there is no way that these could be positioned remotely from the windows of habitable rooms. Added to which, costly scaffolding will be required for installation at height. And then there is the issue of access for maintenance…. What a complete mess.

  13. MrGrimNasty permalink
    June 2, 2022 6:26 pm

    CET meddling. May 2022 apparently.

    The links I previously used seem dead. I guess this explains it.

    But please let’s not pretend May has not been another warm month in a record warm start to the year, by a massive margin.

    • Phoenix44 permalink
      June 3, 2022 9:13 am

      UAH global satellite anomaly for May was 0.17 degrees, down from April. Pretend? You seem to be the one making mountains out of molehills

      • MrGrimNasty permalink
        June 3, 2022 11:13 am

        Were talking about the CET, as you full well know is running a massive record high Phoenix, surely you’re better than that dishonest diversion.

  14. that man permalink
    June 2, 2022 8:49 pm

    Paul refers to his previous post, which mentioned the ‘record’ temperature recorded at Heathrow. Obviously the UHI effect is significant, but to dismiss the additional contributions of huge turbofans as a ‘red herring’ is nonsense. See for a well-reasoned analysis.

    • MrGrimNasty permalink
      June 2, 2022 10:41 pm

      It is a red herring, see above.

  15. Mike McWha permalink
    June 2, 2022 9:38 pm

    “ No doubt there is a sensible reason for this!”. Where to start. Must still be using the old spreadsheets!! Time to do a data audit.

    • catweazle666 permalink
      June 2, 2022 10:00 pm

      Are you sure they’ve advanced beyond the abacus?

  16. Coeur de Lion permalink
    June 3, 2022 9:13 am

    Oh, and how much global CO2 does UK emit? One per cent near enough. Futile futile futile – not even virtuous. Silly silly

    • catweazle666 permalink
      June 3, 2022 3:46 pm

      That’s around 1% of anthropogenic CO2 actually, anthropogenic CO2 comprises around 4% of the global CO2 cycle.

      • Chaswarnertoo permalink
        June 4, 2022 11:01 pm

        0.004 %. Not measurable.

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