GEOGRAPHIC EXTREMES SOCIETY
AUSTRALIAN RECORDS
Heat
Australia is a hot country with a vast arid interior, which has low humidity and sparse cloud cover. Not all heat is the same. Humidity plays a huge role in how comfortable we feel. Most people prefer dry heat to the cloying, oppressive humidity of the tropics. In hot, dry climates, our sweat evaporates, cooling the blood vessels close to the skin and lowering our body temperature. But, in hot, humid climates, our perspiration doesn’t readily evaporate on the surface of the skin, making a person feel hotter.
Apparent Temperature
The point to make is that the perception of being hot is different to all of us. Over the years, the Bureau of Meteorology has attempted to address this issue, and as a result, they’ve introduced a new feature into the weather forecasts, called, ‘feels like’. It is basically another name for ‘apparent temperature’. The world record for a ‘feels like’ temperature is 81oC in Dhahran, Saudi Arabia, recorded on July 8, 2003.
Historical heat records
To collate our accurate climate data, meteorologists need trustworthy devices for the uniform recording of weather throughout Australia. In the absence of identical recording devices, there have been many instances of improbable temperatures recorded. For example, explorer Charles Sturt recorded a temperature of 127oF /52.7oC on November 11, 1845. As we will discover, this was extremely early in the season to achieve such searing heat. His thermometer later burst when he placed it in the crook of a tree during this heatwave, not far from Fort Grey near Tibooburra in north-western New South Wales. No one doubts that Sturt recorded this temperature, but for the Bureau of Meteorology to consider the data as accurate, it must come from a standardised recording device.
The Bureau performed an inventory of temperature records, in the late 1990s, to examine historical temperature records. One claim that stood out to the principal researcher was the record temperature from Cloncurry in north-western Queensland on January 16, 1889, of an incredible 127.5oF /53.1oC. As a result of the inventory, this record and numerous others disappeared from the Bureau’s historical database.
Cloncurry’s record came into disrepute because of the inappropriate material used to house the thermometer. It would appear obvious to anyone today that a wine-crate hanging over the town’s thermometer would fail as housing for a temperature recording apparatus.
Sign at entrance to Cloncurry. Image RJ Andrews
The standard housing for an apparatus to measure temperature and humidity has, for almost 150 years now, been the Stevenson Screen. For his part, Thomas Stevenson developed a specialised enclosure to standardise measurements after inconsistent readings from similar devices at the same location. The Stevenson Screen has evolved, but the concept remains the same: a double-louvred wall with a double-roof, housing equipment used to measure temperature and humidity.
The Stevenson Screen Image: BoM
Along with the Cloncurry record, there have been many more temperature records recently relegated to obscurity, due to a variety of reasons. The Post Office at Bourke on the Darling River in New South Wales recorded a temperature record of 125oF /51.4o C on January 2 and 3, 1909. The January 2 recording was later corrected to 112oF by the observer, while the 125oF record for the January 3 was left intact and ceremoniously, underlined. The BoM researcher undertaking the inventory determined that the 125oF recording was markedly higher than neighbouring but quite distant stations at Walgett, Coonamble and over the Queensland border to Thargomindah. On that very same day, the much closer town of Brewarrina had a 123oF reading on a thermometer located on the veranda of the post office but not in a Stevenson Screen. The BoM dismissed the Bourke record, mainly for the fact that it fell outside the probability of legitimacy concerning surrounding stations.
Highest Australian Temperature
When we dismiss these two discredited claims, the highest temperature was at a Bureau of Meteorology station in Oodnadatta, South Australia, by a lone staff member in the stifling summer of 1960.
On January 2, 1960, Oodnadatta recorded an eye-watering 50.7oC at the Bureau of Meteorology station at the nearby airport. At the time, this temperature wasn’t an Australian record, as the Cloncurry record still stood back then.
Back in 1960, I’d like to think the lone staffer had a tinge of excitement when he observed the record temperature. A genuine 50oC plus day is incredibly infrequent; in fact, a search of the Bureau’s current records shows that it has only happened three times.
Oodnadatta Weather Station. Highest Australian Temperature. Image: RJ Andrews
Heatwaves
Temperatures this hot are invariably embedded in heatwave events. For the more significant part, Australian heatwaves begin to form with temperature surges over the Pilbara and Murchison region of Western Australia before slowly, over a few days, move with prevailing wind currents, drifting eastwards over central and on to south-eastern Australia. The Bureau of Meteorology defines a heatwave as three or more days of high maximum and minimum temperatures that are unusual for that location. Still, I prefer the South Australian assessment, which determines heatwaves as five or more consecutive days above 35oC.
Movement of heatwaves across Australia. Image BoM
During heatwaves, high-pressure inversion layers trap the excessive heat, forming a large dome within the high-pressure system. These domes of heat are sometimes as large as 1,000 kilometres wide, which gradually drift east within the high-pressure system. The inversion layers stop the convection that would typically dissipate the heat. As the high-pressure systems then float over the inland deserts, they can gather even more heat before progressing into south-eastern Australia. To achieve temperatures approaching the 50-degree benchmark, a few days of exceedingly hot temperatures must precede the day, allowing the night-time temperatures to creep up. As a record-breaking day dawns, the wind needs to die down, and the cloud cover has to be at a bare minimum. At this point, the Sun starts heating the dome of already pre-heated air, and the barometric pressure will slowly drop. Between 11.30 am and 2.30 pm, it may be possible to get temperatures in the high 40s, or if conditions are exceedingly optimal, you’ll see a rare 50-degree day.
In 1960, the night-time ‘minimum’ temperature on January 1 and 2 was a sweltering 36.4oC at Oodnadatta. The intense heatwave which developed during those early weeks of January 1960 affected people across Australia. In Sydney alone, heat-related stress claimed twenty-five lives [3], and around the nation, people swamped hospitals emergency rooms, due to effects of the heatwave.
Longest Heatwaves
Throughout Australia, the perception is that Marble Bar is the hottest town in Australia. The region certainly experiences sweltering temperatures, and it surprises no one that Marble Bar regularly tops the list of the hottest daily temperatures nationwide.
Marble Bar has the reputation of having over 160 consecutive days of temperatures exceeding 100oF/38.7oC. This phenomenal record-breaking streak of hot days was set in the town’s mining heyday from October 31, 1923, to April 7, 1924.
Marble Bar. Historically, the hottest town in Australia. Image Marble Bar Tourism
But these days, she continued, the townsfolk were all talking about the Rabbit Flat record of March 2019. Rabbit Flat is on the Tanami Track near the Northern Territory-Western Australia border, another sweltering place. Its record-breaking spell of 115 days above 39o C beat Marble Bar’s record of 106 days.
To alleviate the inconsistencies, the bureau introduced ACORN-SAT: the Australian Climate Observations Reference Network – Surface Air Temperature. In 2011 the first version was launched by the Bureau of Meteorology as cutting-edge technology to help guide scientists, political decision-makers, business and the agricultural community to make informed choices on topics like climate change. Computer algorithms recalculated temperatures and revised them up and down as necessary.
In a nutshell, from the beginning, the system was a disaster. Climate change sceptics were quick to pounce on the failings of this new system. To give you an example of the issues ACORN has faced, Version 1 listed the hottest day in Australia as 51.2oC on February 8, 1933, in Albany, down in the far south-west of Western Australia. It can get hot in Albany, but its seaside location ensures that those optimal conditions for extreme temperatures just can’t develop.
Version 1 was proven to be misleading, so a new, improved version was required. The Bureau of Meteorology launched the second version of ACORN-SAT in 2019.
Version 2 saw improvements made and a few records, including the highest temperature at Albany, have to be thrown out the window. Still, it meant that Oodnadatta retains the Australian temperature record.
According to adjustments by ACORN-SAT modelling, Marble Bar’s heatwave record of consecutive days equalling or exceeding 100F (37.8C) has been:
RAW 160 days from 31 Oct 1923 to 7 April 1924 (average temp 42.7C)
ACORN 1 129 days from 31 Oct 1923 to 7 March 1924 (average temp 42.6C)
ACORN 2 128 days from 1 Nov 1923 to 7 March 1924 (average temp 42.4C)
While Marble Bar’s records are tumbling and Rabbit Flat Roadhouse is quickly taking on the mantle of Australia’s ‘Hottest Town’, neither maintains the record as the ‘Town with the hottest average temperature’.
Hottest Average Temperature
This claim belongs to Wyndham at the very top of Western Australia. I find it remarkable that a town situated on the coast can achieve this feat, but the trick to making Wyndham so hot lies in the surrounding hills which trap the humid air and heat at night.
Wyndham. Hottest average maximum temperature in Australia. Image: BVPVisuals.com
The Wyndham locals laughingly refer to a feeling of being in a constant roast chicken rotisserie, with the only July offering respite of cooler temperatures. One of the council staffers even claimed that the official temperature gauge exploded in December 2018.
Records here, stretch back to 1886 and the Bureau of Meteorology have maintained a large weather radar in Wyndham. I notice that their recording stations have gradually moved around the town to increasingly hotter surroundings. The first station started down at the port, recording an average maximum temperature of 34.6oC. When the central part of town moved away from the mangroves and the port, the recording station shifted with the post office where it listed an average maximum temperature of 35.6oC. The weather station finally relocated more inland to the airport, giving us an average maximum temperature of 36.0oC.
Heat Records
Charles Sturt recorded 127oF (52.7oC) on November 11, 1845 – Dismissed
Cloncurry January 16, 1889 127.5oF (53.1oC). – Dismissed due to temperature gauge housing
Bourke 125oF (51.4o C) on January 2 and 3, 1909 – Dismissed due to observer error.
GES Record: Hottest temperature recorded in Australia – Oodnadatta 50.7oC. On January 2, 1960. (Source: Bureau of Meteorology)
Consecutive days above 100oF – Marble Bar
160 consecutive days of temperatures exceeding 100oF (38.7oC) – Raw Data
128 days from 1 Nov 1923 to 7 March 1924 – ACORN-SAT 2
Consecutive days above 39o C – Rabbit Flat
115 days (beating Marble Bar’s record of 106 days)
GES Record: Hottest Town – Wyndham, average yearly maximum temperature 36.0oC (Source: Bureau of Meteorology)
The Geographic Extremes Society welcomes any input as to the veracity of these records and we encourage everyone to contribute to these extreme records by contacting us to initiate the discussion