A cool change is expected to sweep across Victoria this evening, but not before temperatures hit the low 40's in the north-west of the state.
Bureau of Meteorology senior forecaster Tom Delamotte said northerly winds would push temperatures up to 43 degrees, in Mildura, and 38 in Melbourne.
The CFA has issued total fire bans for the Mallee, Wimmera and north country districts.
"The strongest winds will be later today," Mr Delamotte said.
"We are forecasting dust across the north-west again, particularly with the strong south-west change, moving up through the area.
"We do expect the dust to become quite thick, across Mildura, later today potentially."
The cool change would be gradual, across the inland, with temperatures dropping by about 10 degrees, over two to three hours.
"We'll then go back to milder conditions, with south-westerly winds, at least through until Saturday, but it will still be a bit warmer, along the Murray River," Mr Delamotte said.
Prolonged south-westerlies would see temperatures in the high teens to low 20's, until the weekend.
"The oceans are still quite cold, at this time of the year, so, with these prolonged south-westerly winds, it means lower temperatures."
Mr Dellamotte said the weather pattern was not unusual, for this time of the year.
The Bureau's Long Range Forecasts head Dr Andrew Watkins said the westerly winds would dominate Victoria's weather, for the next few weeks.
"They will be keeping things a bit cooler in southern Victoria," Dr Watkins said.
But he said the weather would start to warm up, in the New Year.
"When we get to January and February, those temperatures will start to go up again," he said.
"We are looking are at above-average temperatures later on in the summer, and we are looking at a drier than average summer and a drier period, over the next few weeks."
The east of the state would continue to experience below-average rainfall.
"What we see at the moment is a negative southern annular mode," Dr Watkins said.
'Our weather systems are further north than usual at the moment, that brings more westerly winds, into Victoria and, keeps things a bit cooler, but also brings hot westerly winds into Queensland and NSW."