The city last month sweltered through its hottest temperatures since the Bureau of Meteorology began tracking weather at the Bendigo Airport in 1992.

Mean maximum temperatures for the first month of the year were 36 degrees, six above the average, though not all yesterday’s data was yet to be added to totals.

BOM duty forecaster Miriam Bradbury said Thursday temperatures would likely help lower totals slightly, but most likely not enough to stop towns including Bendigo, Maryborough and Echuca rewriting history books.

Echuca’s average mean temperature record of 35.1 degrees, set in 1981, looks set to be broken by nearly two degrees.

Maryborough’s 32.6 degrees, set in 1969, could be busted by about 1.5 degrees.

Bendigo could smash last year’s January high of 33.5 degrees.

The city already broke the highest temperature recorded at the airport last Friday with 45.9 degrees and this month’s mean minimum was 16.5 degrees, equal to the previous high from 1995.

Many central Victorian towns had seen four Januaries in a row with above average heat, Ms Bradbury said.

National temperatures were “unprecedented”, BOM senior climatologist Andrew Watkins said, with averages exceeding 30 degrees for the first time in any month.

The main contributor to that heat was a persistent high pressure system in the Tasman sea which blocked any cold fronts and cooler air from impacting the south of the country.

"At the same time, we had a delayed onset to the monsoon in the north of the country which meant we weren't seeing cooler, moist air being injected from the north,” Mr Watkins said.

"The warming trend which has seen Australian temperatures increase by more than 1 degree in the last 100 years also contributed to the unusually warm conditions."

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