Parts of Australia experienced sub-zero temperatures, whilst other soared to above 40 degrees.
Parts of the country sweltered while others experienced surprise snow in the first week of summer.
Parts of south-east Australia, including NSW, Victoria and Tasmania, experienced snowfall as temperatures fell into the negatives.
Meanwhile, in Queensland and Western Australia, temperatures reached as high as 46 degrees on Saturday.
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It was also a hot weekend in Sydney, with parts of the city's west soaring above 40 degrees.
It was also a warm start to the week, but rain is set to sweep across Sydney soon, with up to 20mm set to fall on Thursday.
Bushfires also struck parts of NSW, Western Australia and Tasmania, with one firefighter dying on Sunday.
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By contrast, temperatures plummeted to -4 degrees in Thredbo on December 2, with Canberra also experiencing its first sub-zero temperature in summer, dropping to -0.3 degrees the same morning.
The contrast in temperatures between the snowfields of Thredbo and the 46 degrees seen in Birdsville, Queensland, means there was a 50-degree gap in temperatures between different parts of the country.
"The first week of the 2025-26 summer, which started on December 1, saw two contrasting air masses jostling over Australia," Weatherzone's Ben Domensino said.
"Cold air originating from the Southern Ocean swept over parts of the county in the first few days of the week before a large pool of hot air spread across the continent."
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