A large area of Australia will endure an intense heatwave during the final days of 2019.

Hot weather happens every summer, and Australia is home to some of the highest temperatures in the world. Unfortunately, this summer has already produced record-breaking heat and another fierce heatwave is set to sweep across the country during the final days of December.

- Why so hot? -

A delayed start to the northern wet season has combined with a decaying positive Indian Ocean Dipole and negative Southern Annular Mode to produce exceptionally hot and dry weather in Australia this month.

The resulting 'dome of heat' has been wafting around Australia throughout December, causing inland areas to bake in persistent and extreme heat, while coastal regions fluctuate between very hot and relatively mild days.

- Records broken -

The country as a whole set new national maximum temperature records twice in as many days during the middle of last week. December 17th and 18th were Australia's hottest days for any month of the year, based on an average of the maximum temperatures measured across the country on each day. Impressively, the maximum temperature of 41.9 degrees on the 18th was a whole degree above the one-day-old record of 40.9 degrees on the 17th.

In addition to these national-scale records, a number of individual locations have also registered previously unobserved temperatures during the last couple of weeks.

Nullarbor's 49.9 degrees on December 19th a new national December record and the fourth highest temperature reliably recorded in Australia during any month, according to the Bureau of Meteorology's online climate database. 

On Christmas Day, Rabbit Flat's 47.9 degrees was the Northern Territory's highest temperature on record for December and third highest on record for any month. Further south, Alice Springs Airport (45.7C) registered its highest all-time temperature on record on the same day.

Impressively, the lowest temperature observed at the Northern Territory's Walungurru Airport (Kintore) during Christmas night and Boxing Day morning was 36.0 degrees. This is the highest December minimum temperature on record in Australia, beating 35.0 degrees at Marble Bar in 1902. It's also the country's third highest minimum temperature for any month, beaten only by 36.6 degrees at Wanaaring (NSW) and 36.1 degrees at Moomba (SA) in January this year.

This month's persistent heat has also broken a number of multi-day records. 

Thursday was Darwin Airport's 20th day at or above 35 degrees so far this December. This is the highest number of days this hot during any individual calendar month since records began at the site in 1941. The previous record was 13 days in October 2009, while the previous December record was nine days in 2002.

- Heatwave rolls on -

Looking ahead, the mass of hot air that has baked much of Australia during the last few weeks will continue to plague the country as 2019 draws to a close.

Severe to Extreme heatwave conditions are forecast to affect parts of Western Australia, South Australia, Victoria, New South Wales, the ACT, and Tasmania between Friday and the middle of next week.

Image: Forecast surface temperature on Monday, December 30th, according to the ECMWF-HRES model.

While the highest temperatures during the next week should be lower than last week's near 50-degree maximums, some places are likely to exceed 45 degrees. Adelaide, Melbourne, Hobart, Canberra and western Sydney are all forecast to see at least one day in the high thirties or low forties before the end of 2019. Darwin could even add another day or two to its record number of days over 35 degrees before December draws to a close.