"It dropped down to 28.1 around midnight and that beats the record by a long way," said senior forecaster Phil King.

"The previous minimum was 26.2 degrees set on November 25, 1901, so it's a record warm November and by a significant margin."

Mr King said with the heat came elevated fire danger levels, which approached dangerous levels about 1am.

"Not only was it a warm night, but the fire danger levels were into the severe range for a number of hours," he said.

Victoria today faces its greatest bushfire threat since the Black Saturday infernos as potentially disastrous conditions sear huge areas of the nation.

After an uncomfortably hot night, most of Victoria is subject to a "severe" fire danger alert today, with northerly winds tipped to drive temperatures well into the 40s in the north-west, north and north-east.

Temperatures are expected to reach 42 degrees in parts of Victoria late this afternoon, with relative humidity down to 6 per cent and winds averaging 30 km/h.

Melbourne is expected to reach 34 degrees today and experience another hot night before a cool change moves across the state about midday tomorrow.

New South Wales is also expecting extreme temperatures, with 39 in Sydney and 45 degrees in the west of the state, including Broken Hill.

Central Queensland residents also face the possibility of evacuations today as authorities warn two fast-moving bushfires are headed their way.

And Canberra has declared a total fire ban for today with temperatures expected to reach 37.

Temperatures in Tasmania are forecast to be near 30 degress with 29 predicted for Launceston.