Heatwave, snow records being broken in Australia! The data record begs to differ.

With the usual breathless hysteria that has become the mainstay of journalism, the above article goes on to claim that temperatures will plummet to 16C after Hobart saw a record 40.9C – “its hottest day ever”. More of the usual journalistic alarmism playing to the narrative that 21st century temperatures are the highest on record.

The meteorological station in Hobart is located in a built-up area on Ellerslie road and has a nearly continuous temperature record dating from 1882.

Ellerslie Road highest and lowest monthly temperatures (Data: Bureau of Meteorology data for station, 94029)

The graph of the maximum and minimum temperatures for Ellerslie Road shows that 2013 was in fact the highest temperature in the record with a warm 41.8C, but temperatures were comparable in the late 1800s as can be seen. While the maximum temperature is expected to see 16C, this is nothing unusual.

On 30th December 1897 the thermometer recorded 40.6C but fell to 17.4C two days later and was 14.6C a few days before on the 20th December 1897. This is the period of the worst drought in Australia, the Centennial Drought and this high temperature was followed by another record on 1st January 1900 with a peak of 40.6C when only days before, on the 27th December 1899, the maximum was a mere 14.6C.

In Tasmania these temperature fluctuations are nothing uncommon.

Mount Wellington covered in snow after 40C day. (Supplied/Adrian Van Beek)

More interestingly there is a long-term upward trend in both the maximum and minimum temperature data for Ellerslie Road, which is evident in the Mean Maximum Temperature Anomaly map (using a mean of 1882-2020). However, the overall temperature trend seen in other Australian data of high temperatures around 1900 and comparable temperatures today is evident in the data.

Ellerslie Road mean maximum temperature anomaly (Data: Bureau of Meteorology data for station, 94029)

While this might reflect a long-term temperature change for the Hobart region it might also be related to the location of the meteorological station which is now surrounded by roads, houses, car-parks and multistorey buildings.

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Ellerslie meteorological station location in a heavily built-up region of central Hobart, Tasmania.

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