Average maximum temperatures were 1.61 degrees above the 1961-90 average, according to Bureau of Meteorology data, narrowly exceeding the previous record for the period set in 2002.

As much of the country's centre and southern regions wilt under a heatwave, the bureau predicts this summer will continue to bring above-average temperatures.

“Odds are in favour of hotter and drier conditions to the end of March,” Karl Braganza, manager of climate monitoring at the Bureau of Meteorology, said.

Maximum temperatures are set to hit 45 degrees for as long as a week in desert regions, while large areas of New South Wales, Victoria and South Australia are likely to see the mercury reach 40 degrees or more each day for the period.

The extreme heat comes after a year in which much of Australia went from wetter and cooler conditions to hotter and drier ones by the end of December.

The overall figures for 2012 show the average temperature for the year was 0.11 degrees above the 1961-90 average of 21.81 degrees. Rainfall averaged 476 millimetres, compared with a 465-millimetre average over the 1961-1990 period.

The bureau noted in its report how much southern Australia in particular had dried out during the course of the year.

“The year also saw unusually persistent high atmospheric pressure near southern Australia,” the report said. “This was associated with greatly suppressed westerly frontal and storm activity in south-west Australia, and indeed southern Australia as a whole, and was reflected in very poor winter–spring rainfall in many southern areas.”

Australia may be heading back towards the drier conditions seen before the two recent years of relatively wet conditions.

“That April-to-November period has been dry pretty much since the 1990s, and even in the last few years it has been reasonably dry in between the two really wet summer season,” Dr Braganza said.

“The fronts and changes that are coming through just don't have as much rain in them.”