Victorians should brace to get hot and sweaty over coming days.
Temperatures will reach the high 30s and low 40s across the state on Thursday and remain elevated overnight before hitting a top of 43C in Melbourne on Friday, Bureau of Meteorology senior forecaster Richard Carlyon said.
But a cool change is expected to sweep through on Friday, hitting the metropolitan area by about 3pm.
"It looks like a very punchy cool change," Mr Carlyon said.
"It will be a sharp temperature contrast in Melbourne: 43C ahead of the change but we'll see that temperature drop to the mid- to high-20s behind it, roughly a 15C drop in the first 20 minutes of the change."
During the change, wind squalls of 70-80km/h are expected and a possible thunderstorm with humid conditions on Friday.
The hot weather also presents an increased fire risk, with severe to extreme fire dangers expected later in the week.
