The inland NSW town of Dubbo is on track for a heatwave and is expected to have six days at or above 37 degrees.
“Dubbo’s December average is merely 31 degrees,” he said.
Western Sydney is also expecting a hot run of days, with the temperature tipped to hit 41C on Thursday.
“Richmond is set to exceed 35 degrees each day from Wednesday to Saturday, its hottest December spell in at least 12 years,” Mr Sharpe said.
“Sydney itself will see seven straight days above 27, with unseasonably humid nights above 20 degrees from Wednesday night into the start of next week.”
South Australians can expect some relief from the hot conditions with the capital set to reach 36C today and 38C tomorrow.
“The heat will leave abruptly as a cool change arrives late on Wednesday, dropping the temperature by about 10 degrees in an hour near dinner time,” he said.
“On Wednesday, Melbourne will see its hottest day since last summer, likely reaching 36 degrees.”
The town of Yarra Glen, 40km north east of Melbourne, is set to reach temperatures of 30C, 36C and 28C.
In NSW, around half of the state has already begun experiencing a low-intensity heatwave that will strengthen as the week goes on, according to the Bureau of Meteorology.
Things are also heating up in Queensland.
The outback town of Birdsville will hit 42C today, 43 tomorrow and 43 on Thursday.
The average mean maximum temperature for December is 37.7C, BOM statistics show.
The inland town of Richmond is expecting a top of 39C today, 39C tomorrow and 41C on Thursday.
The highest temperature recorded for the town has been 26C so far this month.
Here’s what the weather will look like across the country this week.
SYDNEY
The city can expect a top of 27C today, 30C tomorrow, and 33C on Thursday.
Temperatures will be even hotter in the west, which can expect highs of 34C, 38C and 41C.
BRISBANE
The capital of the Sunshine State will hit a high of 29C today, 30C tomorrow and 31C on Thursday.
MELBOURNE
The city will hit temperatures of 26C today, 36C tomorrow and 27C with the chance of showers on Thursday.
HOBART
The capital will hit a high of 25C today and 31C tomorrow before a cool change brings the mercury down to 23C on Thursday.
CANBERRA
The Australian capital will hit a high of 31C today, 34C tomorrow and 34C on Thursday.
DARWIN
The city will reach 35C today, 34C tomorrow and 34C on Thursday with showers and possible storms expected.
PERTH
After a stinking hot start to the week yesterday, Perth is set to cool down a little with the mercury hitting 29C today, 27C tomorrow and 29C on Thursday.
ADELAIDE
The city will hit a top of 36C today, and 38C tomorrow before a cool change brings the temperature back down to 24C by Thursday.