The temperature in the centre of Melbourne reached 39.2 degrees at 3.20pm on Friday, according to the Bureau of Meteorology, marking the first time it has passed 38 since 2018.
At the same time, the temperature at Melbourne Airport hit 40.6 degrees.
A fire broke out alongside the Monash Freeway in Hawthorn in inner Melbourne about 1.45pm amid the high heat, causing significant traffic delays with three outbound lanes of the freeway having to be closed.
Firefighters managed to bring the blaze under control by 2.25pm.
A cool change is expected to bring relief to Melbourne from 4pm, according to the bureau’s Dean Narramore.
“We’re expecting the cool change to travel through southern Bayside suburbs around 4 to 5pm, then through the city to 5 to 6pm, and outer suburbs after that,” he said.
“It will be an abrupt change with temperatures dropping anywhere from five to 10 degrees.”
Narramore said it was a tale of two extremes in the country as the Top End and northern Queensland see heavy rain and flooding while the west and south swelter through a heatwave.
”The heat has been sitting in Western Australia for a few weeks but now the heat is dragged to central and south-east parts of the country over the last few days,” he said.
The extreme fire danger conditions sparked a total fire ban for Central and North Central districts from the Country Fire Authority.
For the weekend, the heatwave is set to move into NSW bringing a peak of 31 degrees in Sydney on Saturday and up to 38 degrees in the city’s western suburbs.
Water temperatures will also be lovely in Sydney this weekend in the mid to upper 20s as the heatwave brings people in droves to the beaches.
The heat will move into southern Queensland too over the weekend and early next week.
The heatwave is bringing an elevated fire danger with high to extreme warnings for central Victoria today and more to come for NSW at the weekend.
But Queensland’s north is preparing for flooding with severe weather warnings in place for Cairns, Cooktown and Port Douglas.
Narramore said there were falls in excess of 300mm in the Daintree Rainforest last night.

Western Australia is set to continue cooking today and into the weekend with the possibility of temperatures reaching 40 degrees in the region’s north.
”The focus of extreme heat will be around the Pilbara with temperatures of 46 to 48 degrees expected,” Narramore said.
In January last year, Mardie, Onslow and Roebourne reached above 50 degrees and the bureau said this could happen again at the weekend.
”That’s the third or fourth time we’ve seen temps in Australia record temps above 50 degrees,” Narramore said.
The ACT will also be hot, with Canberra forecast to reach 33 degrees on Friday before pushing up to 35 degrees on Saturday, with a possible thunderstorm on the forecast.
Brisbane is looking at a top of 31 degrees on Friday and staying much the same across the weekend.
Further south though, in Perth, it will be a much cooler 28 degrees before the mercury jumps up to 34 degrees on Saturday, in line with those models.
In Darwin, it’ll be 33 degrees and thunderstorms across Friday, Saturday and Sunday.
The prolonged heat conditions come as Narramore predicts warm temperatures will last longer this year as La Nina conditions ease.