Temperatures have been been scorching for residents in Mildura, who contended with a sticky night before the mercury reached a top of 46C on Friday.

Relief isn't in sight yet, with the Bureau of Meteorology predicting the border town will reach a top of 43C on Saturday.

A cool change shifts the hot weather on by the evening.

The state's northern towns and cities have been struck by a heatwave, with conditions mostly unchanged since Thursday.

Albury Wodonga, Wangaratta and Echuca will see temperatures in the low 40s on Saturday before cooling down by Sunday.

State Health Commander Paul Holman has reminded Victorians to "remain vigilant" during the coming days, keeping an eye on elderly people and young children, who are less able to regulate their body temperatures in extreme weather.

Originally published as Heatwave continues in Victoria's north