David Bidstrup. Which temperature record would you like?

It’s been a bit cold here in Adelaide. The last few mornings have been bracing to say the least, particularly when the dog demands her early morning walk on the beach at 5.30 a.m.

The local rag had a story about how June 10 was the coldest morning “in 75 years” so I dived into the records to check.

Those who are familiar with Adelaide will know that the main BoM station is on West Terrace. The earliest records I can find start in 1887 but it was closed for 38 years between 1979 and 2017 before starting again. In that period the official station was located at Kent Town which is about 1 ½ miles East of the West Terrace site. Kent Town ended its “official” life” in 2017 but records are still taken there to this day and can be found on the BoM website. The other site that is relevant is Adelaide Airport, again about 1 ½ miles from West terrace but to the west. It started recording in 1955.

The upshot of all this is that there is a choice of 3 “official” BoM stations, all close together and in similar surroundings, where one can find the “record” maximum or minimum.

Here are the minimums for June 10 2020:

West Terrace: +0.9.  Airport: -0.4   Kent Town: +1.2.

So there is a range of 1.6 degrees between the extreme “records” for the day.

Looking at the total data, the records are:

West Terrace: Highest T Max 46.6, lowest T Min +0.6.

Airport: Highest T Max 45.8, lowest T Min -2.6.

Kent Town: Highest T Max 47.7, lowest T Min -0.4.

The range for T Max temperatures is 1.9 degrees, for T Min it is 3.2 degrees.

We are told that the minimum of 0.9 reported for 10 June 2020 was the “coldest for 75 years”, the next “record” being 0.8 on 24 June 1944 however they omit to tell us that there was a minimum of 0.9 on August 7, 1888 and a similar “record” of 0.8 in 1913 if the West Terrace data is used.

Using Kent Town there was a morning of 0.9 in June 2014 and 0.8 in both 1982 and 1983. The Airport had minimums of 0.8 in 2006, 1978, 1968, 1964, 1962 and 1961 and also had a total of 76 days with a minimum less than 0.9, the lowest of which was -2.6 in June 1982.

The pedants will argue that each station “is unique” but I disagree. Here the 3 are very close together but their readings vary considerably. Which one is “the record”?

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9 Responses to David Bidstrup. Which temperature record would you like?

  1. stevem

    The answer is obvious. For the media it’s always the station that will provide the most sensational result. This is further enhanced by the ability to conflate one station with another during times when continuous records are unavailable.
    For rabid global warmists the same rules apply, except that low temperature extremes should be ignored.

  2. Tim Neilson

    Don’t fret about it David.

    It will soon be homogenised away anyway.

  3. Pyrmonter

    David

    There are time series of weather observations for ‘Adelaide’ going back to 1839: the BoM rainfall data include them, but not the temperature data, I believe because the Stevenson frame was implemented then. West Terrace referred, from the 1870s to the 1940s, to the Adelaide Observatory, a combined residence and workspace for the Government Astronomer, from 1870 Sir Charles Todd. It was on the site on which Adelaide (formerly Boys) High School stands; I believe it then crossed the road (into a more built up area) before being moved to Kent Town c. 1980.

  4. Leo G

    The pedants will argue that each station “is unique” but I disagree. Here the 3 are very close together but their readings vary considerably. Which one is “the record”?

    The record only applies for the particular weather station.
    It seems to be common practice to assume that the site is representative of a wide area, but that cannot be true. If it were true then the uncertainty in the temperature would reflect the temperature variation across the whole of that area.
    Accordingly each “official” station temperature reading represents only the temperature within the weather station enclosure.

  5. Pyrmonter

    David

    Checking the co-ordinates for the weather stations given on the BoM website, Airport to West Terrace (as the crow flies) is about 3 3/4 miles (over 6km); West Terrace to Kent Town about 2 1/4 miles. Elevation rises c. 26 m, and then 21 metres.

    Airport is about 1.5 km from the coast, so is likely affected by the maritime conditions.

  6. Kneel

    “Here the 3 are very close together but their readings vary considerably. Which one is “the record”?”

    Yeah, well – 3C difference in less than 12km, yet BoM says 1200km is acceptable to “homogenise” each other. Because the “experts” have spoken.

  7. Professor Fred Lenin

    The weater temps were taken in melbourne in Latrobe street at the bureau office it was gradually smothered in huge glass surrounding buildings ,reflecting heat from tinted glass thats probably why the temp readings rose over a few years ,the skyscrapers also blotted out the breezes from the Bay . They didnt thinkto take the temps in Carlton gardens where there was a large open space unhindered by skyscrapers ,bit too hard I suppose.

  8. RobK

    A definition of temperature:

    n. A measure of the average kinetic energy of the particles in a sample of matter, expressed in terms of units or degrees designated on a standard scale.

    Comparing the kinetic energy in a non-descript waft of air from one decade to the next using different instruments and at varying locations, to the last decimal of accuracy of those instruments, is entirely meaningless and unscientific and not the intended use of the data. These type of record statements are a political statements not scientific ones. Too many variables.

  9. mem

    Ask any global warmist individual or group what it would take to prove global warming is a fraud? Their heads explode! QED it is a fraud.

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