Australia has recorded its hottest average daily temperature since records began a century ago.
The national temperature - the average of hundreds of daily readings across the country - yesterday hit 40.3 degrees Celsius.
But the record is not expected to last - the Weather Bureau predicts further scorching temperatures in some parts will set another high.
For the past week, temperatures in Oodnadatta in South Australia's far north have hit more than 45 degrees Celsius.
Temperatures are so hot in some regions that the Bureau of Meteorology's interactive weather forecasting chart has added new colours - deep purple and pink - to extend its previous temperature range that had been capped at 50 degrees.
Recent days have seen the maps displaying maximums ranging from 40 degrees to 48 degrees - depicted in the colour scheme as burnt orange to black.
But in their seven-day forecast this coming Sunday and Monday are showing regions likely to hit 50 degrees or more, coloured purple.
If areas hit 54 degrees or hotter - well above the all-time record temperature of 50.7 degrees reached on January 2, 1960 at Oodnadatta Airport - they will be shown as bright pink.
"The bitumen road's melting but you don't really blame it," local Lynnie Plate told the ABC.
"It's like a ghost town here. People come out in the mornings. My theory is if you get up before the heat then you're much better coping."
On Tuesday the mercury went above 47 degrees Celsius in Oodnadatta. It was also the 10th consecutive day over 40 degrees in the town, 170 kilometres south of the Northern Territory border.
Over the border, Alice Springs has had six straight days above 42 degrees and Yulara near Uluru has had five above 44 degrees - records for both towns.
John Wallington from Outback Ballooning in Alice Springs says the heat has not helped tourism.
"It's hot and it's also unstable - the weather has been a little bit unpredictable for the last days. It's frustrating in our business," he says.
Dr David Jones from the Bureau of Meteorology says the sweltering heat is being felt across the nation."In records going way back to the start of 1911, (Monday) - with an average temperature of 40.33 - is Australia's new hottest day on record," he said.
Dr Jones says the national temperature is the average of between 700 and 800 stations.
"And if we look at maximum temperatures that were recorded at those, average those across country, taking into account the spatial distribution, and then just get a simple number," Dr Jones says.
"So what it tells us really is if you look across Australia, as an average, what was the daytime maximum temperature."
The previous all-time high was in 1972.
Dr Jones says Tuesday's temperatures may beat Monday's record by another 0.1 or 0.2 of a degree.
"The other record that we'll be watching is a run of very hot days," he says.
"We'd only ever seen four days of 39 degrees or above consecutively. We've now seen six, and we'll almost certainly see seven, and perhaps even eight.
"So, this event is now going beyond anything in our record books."
Back in Oodnadatta, there is no end in sight to the heatwave with the next six days forecast above 40 degrees.
"If you look at the weekly forecast, or dwell on the last 10 days you'd get a bit depressed, so I just look at the daily forecast," Ms Plate says.
"I looked tomorrow and it's 41; I think beauty - that's a cool change."
Hottest days on record
State by state:
- NSW: 49.7C, Menindee, January 10, 1939
- ACT: 42.2C, Canberra, February 1, 1968
- NT: 48.3C, Finke, January 1, 1960
- SA: 50.7C, Oodnadatta, January 2, 1960
- Qld: 49.5C, Birdsville, December 24, 1972
- Tas: 42.2C, Scamander, January 30, 2009
- WA: 50.5C, Mardie, February 19, 1998
- Vic: 48.8C, Hopetoun, February 7, 2009
- Sydney: 45.3C, January 14, 1939
- Canberra: 42.2C, February 1, 1968
- Darwin: 40.5C, October 17, 1892
- Adelaide: 47.6C, January 12, 1939
- Brisbane: 43.2C, January 26, 1940
- Hobart: 41.8C, January 4, 2013
- Perth: 46.2C, February 23, 1991
- Melbourne: 46.4C, February 7, 2009