Australia has lived up to its reputation as a land of extremes during the last 24 hours, with temperatures ranging by almost 50ºC across the country.

A cold air mass passing over southeastern Australia on Thursday saw a mix of wintry weather affecting Tasmania, Victoria and NSW.

The combination of cloud, rain and cold air saw some places register their coldest November day in decades. Sydney's top of 15.6ºC on Thursday was the city's coldest November day in 24 years, although most of the day felt more like 10-12ºC due to wind chill. In fact, this would even be considered a cooler-than-average day in the middle of winter.

Temperatures plummeted even further in the alps, delivering a dusting of late-season to some of Australia's ski resorts. The mercury dropped as low as -3.7ºC at Mount Hotham late on Thursday night.

But while southeastern Australia was shivering on Thursday, it was a completely different story in the northwest.

Image: Modelled surface temperature on Thursday afternoon.

An extremely hot air mass over northern districts of WA saw the mercury edge above 45 degrees in the Kimberley. Fitzroy Crossing reached 45.2ºC on Thursday after hitting 45.3ºC on Wednesday. If confirmed, this will be the site's warmest pair of November days in five years.

The temperature difference between Fitzroy Crossing on Thursday afternoon and Mount Hotham on Thursday night was 48.9ºC.

Looking ahead, the seasonable heat over northwestern Australia will contribute to elevated fire danger in WA over the next several days. Extreme fire danger ratings are forecast in some northern and eastern parts of the state this weekend, before the scale tips into Catastrophic ratings on Monday.

In southeastern Australia, temperatures will remain cooler-than-average during the next few days before becoming warmer early next week.