Melbourne's in for a muggy night ahead of Friday's stinker.
The mercury's set to hit 42C tomorrow during our worst heatwave in three years.
"It will take quite a while to cool down overnight and not getting all that cool," said Senior Meteorologist Dean Stewart. "Those northerly winds will start to pick up in the early hours of the morning and prevent the temperature falling much further than that."
The news has firefighters on high alert – two emergency warnings already issued for Dreeite South and Mumbannar in Victoria's south-west.
"The fire risk only gets worse with the fact that there's no respite across the state tonight," said Emergency Management Commissioner Craig Lapsley.
While the heat will persist the bureau of meteorology forecasts more cloud cover over the weekend.
There may also be isolated showers and thunderstorms.