Sydney, Melbourne, Brisbane weather: Heatwave blasts the east coast as temperatures soar to 15C above average

A scorching heatwave will spread across Australia’s south-east, leaving millions sweating as temperatures rise up to 15 degrees above average.

Strong northerly winds will combine with a trough to bring the warm weather system to Victoria and South Australia this weekend.

The Bureau of Meteorology (BOM) has issued a fire warning for Mallee and Wimmera, in north-west Victoria, due to high winds and warm weather.

Melbourne reached highs of 37 degrees on Friday and is expected to experience more sultry weather on Saturday before a cool change.

Most northern, central and eastern parts of Victoria are also expected to reach temperatures in the low 30s.

BOM meteorologist Christie Johnson said areas of south-eastern NSW are experiencing temperatures 10 to 15 degrees above average.

Ballarat and Essendon Airport in Victoria and parts of South Australia set records for the warmest November night on Friday.

“Coonawarra in south-east South Australia had its warmest November day, hitting 37.8 degrees Celsius on Friday,” Ms Johnson said.

“We’ve also set some overnight records for minimum temperatures in places like Mount Gambier.”

But the heatwave is coming to an end this weekend, with showers and south-westerly winds set to bring a cool change to South Australia and Victoria.

Ms Johnson said forecasts of thunderstorms with heavy rain could lead to flash flooding in inland South Australia throughout Saturday.

“That storm risk also extends into western Victoria on Saturday, it is associated with the storms ongoing over northern WA and the NT,” she said.

Meanwhile, Sydney will be sweltering all weekend and much of next week.

According to Weatherzone, a high-pressure system off the Tasman Sea has caused hot air to slowly build over the Sydney Basin.

The air mass will also affect eastern parts of NSW until the middle of next week.

Further north, east and inland Queensland will be drenched with showers for most of Saturday.

Northerly winds will sweep the warm weather system into Victoria and South Australia, with the hot conditions caused by a trough (weather map in photo)

Ms Johnson said flood warnings were in force for parts of Queensland as rain that had fallen in recent days moved through river systems and flowed downstream.

The SES received 84 calls overnight from residents of Moreton Bay, the Gold Coast and Brisbane, mainly about leaking roofs as the area was drenched in rain.

A similar weather system will spread through parts of Western Australia, bringing strong winds and heavy rainfall to the northern interior.

Brisbane

Saturday: Possible showers. Maximum 27

Sunday: Partly cloudy. Min. 18. Max. 27.

Monday: Partly cloudy. Min. 19. Max. 28.

Sydney

Saturday: Sunny. Maximum 28.

Sunday: Mostly sunny. Min. 18. Max. 29.

Monday: Sunny. Min. 19. Max. 28.

Canberra

Saturday: Sunny. Maximum 32.

Sunday: Partly cloudy. Min. 14. Max. 33.

Monday: Partly cloudy. Min. 15. Max. 33.

The heatwave will end in Victoria and South Australia this weekend, with showers and south-westerly winds bringing cool conditions (a weather map is pictured)

Melbourne

Saturday: cool change. Late shower or two. Maximum 37.

Sunday: Rain. Min. 18. Max. 23.

Monday: Possible showers. Min. 17. Max. 23.

Hobart

Saturday: Possible showers. Maximum 29.

Sunday: Cloudy. Min. 14. Max. 19.

Monday: Partly cloudy. Min. 12. Max. 21.

Adelaide

Saturday: Rain, tapering off later. Maximum 30.

Sunday: Shower or two. Min. 18. Max. 26.

Monday: Partly cloudy. Min. 16. Max. 26.

Sydney is set to be sweltering all weekend and the heatwave is expected to continue for much of the next week (pictured by people at Bondi Beach)

Perth

Saturday: Sunny. Maximum 29.

Sunday: Sunny. Min. 17. Max. 33.

Monday: Sunny. Min. 16. Max. 28.

Darwin

Saturday: Shower or two. Possible thunderstorms. Maximum 32.

Sunday: Shower or two. Possible thunderstorms. Min. 25. Max. 32.

Monday: Shower or two. Min. 25. Max. 32.