Meekatharra

Meekatharra on a good day.

It's perhaps no accident that the tiny outback town of Meekatharra is an early warning site for the Bureau of Meteorology's weather watchers as they try to estimate what's ahead for Australia's great summer of heat.

Believed to mean “place of little water” in the local indigenous language, Meekatharra has lately been a place of little relief when it comes to scorching temperatures.

Suddenly we're setting record temperatures at a faster rate than you would expect 

On Tuesday, the town in the mid-west region of Western Australia hit 47.1 degrees, smashing its previous maximum temperature by a remarkable 1.4 degrees in a series that dates back to 1944.

“You don't expect to break inland area temperatures by this amount," David Jones, head of climate analysis at the bureau, said.

Measured at an elevation of roughly 500 metres, that blistering heat would be the equivalent of 51-52 degrees at sea-level, he said.

And as a “source region” of Australia's heat, Meekatharra, along with a handful of sites dotted across the country's red-hot heart, offers the bureau one indication of the sort of hot weather areas to the south and east can expect in days to come.

"This is where Australia's air masses get very, very hot," Dr Jones said. Forecasters "look for these high temperatures there because that's the source region for our heatwave", he said.

"These inland regions of Australia are where, if it gets very hot there, you know that if you get a northerly or a westerly, that will be pulled on to the coast and you usually get your very high temperatures in cities such as Adelaide, Melbourne or Sydney."

New records

As predicted, Tuesday saw more records tumble. While the average maximum for the day fell short of setting a new peak, at 40.11 degrees, it was still the third hottest on record. Only Monday's 40.33 degrees and December 21, 1972 at 40.13 degrees was hotter.

Meteorologists, though, point out another record that fell on both Monday and then again Tuesday which is of potentially greater significance than the maximums that have drawn much of the public's focus.

On Monday, Australia's mean temperature – averaging out the minimums and maximums – came in at 32.22 degrees, easily eclipsing the previous record, also from December 21, 1972, of 31.86 degrees. Tuesday saw that record fall again, with the mean coming in at 32.32 degrees, the bureau said, citing the latest figures.

The leap in the mean of almost half a degree is remarkable. A similar range from the previous record would have captured the eight top mean temperatures.

“The extent and intensity of the heat now is clearly unprecedented for Australia for two consecutive days,” Dr Jones said.

Climate 'fingerprint'

Looking through the “weather noise” of daily maximums, the mean temperature provides a clearer “fingerprint of climate change”, said Dr Jones.

“The mean statistic from a climate change perspective is more important than the maximum temperature,” he said.

“At least in the past we used to break records by small margins most of the time,” he said. “This tendency to break records by large margins is really something that's emerging quite quickly globally.”

Victoria, for instance, has clocked up its hottest day for September, October, November and February – and almost in April – in about 10 years, he said.

“Suddenly we're setting record temperatures at a faster rate than you would expect,” he said, noting that the US overnight revealed it had posted its hottest year on record for the lower 48 states, beating the previous record by about 0.6 degrees.

Looking ahead for Australia, cooler conditions are bringing relief to firefighters and the wider populations of the country's south-east. But more hot temperatures - as signalled by Meekatharra - are on the way.

The bureau predicts temperatures may reach 48 at Marree in South Australia on Sunday, while Weatherzone says 50 may be reached on Sunday or Monday, with towns like Moomba in South Australia or Bourke in NSW candidates for that peak.

The all-time record remains 50.7 degrees at Oodnadatta Airport on January 2, 1960.