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”?