One explanation for this

Record-breaking heatwaves have dominated the news recently

In a system with natural variance around the mean then the longer the record of that variance the larger the record deviances from it.

3 sigma events happen more rarely than 2 sigma. But keep records for long enough and you’ll have a 3. And a 4 etc.

We’ve been – accurately – recording temperature for a century or three – dependent upon your definition of accuracy – so one and three century records should be appearing.

15 thoughts on “One explanation for this”

  1. Bloke in North Korea (Germany province)

    And there are 4,264,873 places on the planet where we measure it, at least 24 times a day. And your record event can also be “The x-est ever this place has ever been at exactly this time on an 8th of July since records began”. And we can bravely report only deviations that go in one direction.

  2. I don’t remember such a hoo-hah when we had one of the coldest Aprils on record just a few months ago………or indeed such a big fuss about those polar vortexes that have caused havoc in the US over the last few years, including the one just this year that caused the record freeze in Texas……..

  3. “The searing heat that scorched western Canada and the US at the end of June was “virtually impossible” without climate change, say scientists.”

    Scary

    “In their study, the team of researchers says that the deadly heatwave was a one-in-a-1,000-year event.”

    They have records going back that far?

    “So that’s in a climate without human-induced climate change, when the climate was about 1.2C cooler than it is now. The heatwave would also have been about two degrees cooler in the past.”

    So it would only have been 47.6C rather than 49.6C if it wasn’t for ‘Climate Change’.

    That would have been much better.

  4. Jim, get with the programme son. Cold weather is weather and entirely natural. Hot weather is man made global warming, entirely unnatural and the fault of white man (made an error on another post and forgot to add the ‘white’ bit. Sincere thanks to BiND).

    Proxy records clearly show it was warmer than the present:
    1 thousand years ago – Medieval Warm Period (despite M. Mann et al trying to erase it)
    2 thousand years ago – Roman Warm Period
    3 thousand years ago – Minoan Warm Period.

  5. Just heard weather report in Austria. In the west of the country it is wet and under 20deg, but in the east it is the hottest day of the year do far at 32deg. So global warming is only affecting the Pannonian Plain ?

  6. “We’ve been – accurately – recording temperature for a century or three”: there’s only one set of temperature measurements I trust completely. I ran the town weather station for a few weeks in the summer when I was fourteen or fifteen and bloody fastidious I was too.

    Without wishing to be rude, I’d put my abilities at fifteen above those of the bulk of meteorologists at any age. “Duds” is the technical term for most of them. I did know an apparently clever chap who was appointed head of the Met Office but he was bundled out because of a financial infelicity. It was remarkable that a mathematician didn’t seem to understand the meaning of “greater or equal to”. I suppose he was a chump rather than a dud. Ended up in the Lords, though. Blair, of course.

  7. Paul Homewood has been correcting the misconceptions held by those at the UK Met Office about this matter. There were heatwaves just as high in the 1930s.

  8. Tim,

    “2 or 3 SD etc.”

    You’re assuming that the base trend is flat. It isn’t, it’s upwards. Has been to some degree or other and for whatever reason since the little ice age. Hence, irrespective of any human input, we’d expect (in excess of your estimate) some record high numbers every now and again with various El Nino/PDO/other variations.

  9. Not my point. *Even if* temp were flat then a longer record would still have higher max and minima.

  10. Mohave Greenie in Texas

    The headlines lack perspective. Many of the west coast heat records are from the 1930s and late 1800s (when the planet was much cooler /s). There were no recorded temperatures before 1850. The new records are a degree or two F warmer than the old ones. This is at the noise level of the recording process.

    It must also be noted that there were also some record low maximum temperatures in June, however these don’t get headlines, and are studiously ignored.

  11. Surely, and I write as a non-statistician, it is not the records themselves we should be looking at but the gaps between them. If records are becoming more frequent it is a sign of temperature change in that direction, whether warm or cold. If the gaps are getting bigger, the curve is level or decreasing.

    In the case of climate righ now, tdata can be totally trusted.

  12. “If records are becoming more frequent it is a sign of temperature change in that direction”: or a sign of the urban heat island effect. Or the airport effect. Or just the effect of switching to electronic thermometers which tend to be positioned illicitly near to buildings so that the necessary power cable is short.

  13. A question that I’ve always pondered, but never got to the bottom of, is how do you measure a daytime temperature?

    Is the temperature recorded at the same time everyday? Is it the highest temperature of the day or is it an average over so many hours? Each would give different results.

    If we can’t reliably answer this question, then all is built on sand.

  14. Windypants, try here for unadjusted temps from around the globe: https://temperature.global/#twitter.
    The ‘Team’ (M. Mann, CRU East Anglia et al” adjusted a load of earlier temps., 1930’s especially, due to ‘TOBS’ = Time of Observation Bias. They only adjusted the temperatures downwards, natch.

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