The report also follows a fierce attack on climate change science this week by businessman Maurice Newman, the chairman of Mr Abbott's business advisory group. In a newspaper opinion article, Mr Newman branded climate change a ''scientific delusion''.

Acting Greens leader Richard Di Natale accused Mr Abbott of ''listening to people who are part of the tinfoil hat brigade''. Dr Di Natale said it went against all evidence for the government to unwind the carbon tax. ''The experts right around the world are telling him loudly and clearly that we've got a big problem on our hands and we've got to start taking action to fix it.''

Inland heat



Statewide, Victoria had its third-warmest year, with mean temperatures 1.04 degrees above the 1961-90 average used as the benchmark. It was Tasmania's sixth warmest.



“Victoria and Tasmania had a relatively cool finish to the year – both were below average in November – that just took the edge off things a bit,” said Blair Trewin, senior climatologist at the Bureau of Meteorology.



A blistering start to 2013 was followed by a series of “warm waves” that swept across much of the country at intervals of four to six weeks, and have continued into 2014.



Moomba in South Australia recording 49.3 degrees on Thursday, while Birdsville in Queensland clocked up 48.6 degrees.

Walgett, meanwhile, reached 49.1 degrees on Friday, the highest for NSW since 1939, the Bureau of Meteorology's Dr Trewin said. Other towns to set records on Friday include Moree, Tamworth and Armidale in NSW, and St George and Roma in Queensland.



The hot air mass is slowly shifting east. Brisbane may challenge its record high of 43.2 degrees on Saturday, with 41 degrees forecast.



"That (forecast) would be factoring in some possibility of a sea breeze," said the bureau's Dr Trewin. "If the sea breeze fails, anything could happen."



No El Nino



For 2013, the exceptional heat has been attributed to a delayed monsoon, record warm waters around the country and fewer-than-usual cold fronts.



Inland Queensland and NSW “is also the core of the area that is in significant drought at the moment”, said the bureau’s Dr Trewin: “Because soil moisture is lower than normal, you have less capacity for moisture at ground level cooling the air slightly.”



Climate experts, though, have been surprised national temperature records were broken by such large margins not least because key weather patterns such as the El Nino-Southern Oscillation in the Pacific remained in a neutral phase.



“Australia has set a new record-high temperature in a period when there’s been no El Nino event (and) global temperatures have not increased so rapidly,” said David Karoly, a climate scientist at the University of Melbourne. “So this is particularly unusual.”



Australia’s records “cannot be explained by natural variability alone," Professor Karoly said. "This event could not have happened without increasing greenhouse gases, without climate change."



Unusual weather



Unusual weather patterns have played havoc for some farmers – and backyard potterers - in other ways. September, for instance, posted Australia’s most exceptional heat.



Nationally, maximums were 3.41 degrees higher than average, including 2.74 degrees in Victoria and 5.39 degrees in SA – the most for any state in any month.



While mild by mid-summer standards, the warmth prompted “accelerated or premature development of plant and crops”, the bureau noted last year. Such growth exposed crops to late-season frosts across several states.



Professor Will Steffen, a climate scientist at the Australian National University and a member of the Climate Council, said temperature trends have been “sharply upward” since the 1960s and predicted 2013 will look a lot less remarkable in years to come.



“When you accumulate more heat in the atmosphere, the odds are you’re going to see more high-temperatures records broken,” Professor Steffen said.

“If we keep emitting (carbon dioxide) at the rates we are now, in another three or four decades, 2013 will look like an average year - perhaps even a cool year.”