The World Meteorological Organisation's annual climate statement released last week at Copenhagen found temperatures in 2009 reached 0.44 degrees above the 1961-1990 annual average.

"The decade 2000-2009 is very likely to be the warmest on record," WMO secretary general Michel Jarraud told reporters at the Copenhagen climate summit.

Australia was singled out for its wild weather in 2009.

"Australia had the third-warmest year on record with three exceptional heatwaves," Mr Jarraud said.

The WMO report said the heatwaves happened in January/February, when the hot weather contributed to the disastrous Victorian bushfires, in August and again in November.

The presence of El Nino conditions underway in the Pacific saw near-record rises in sea surface temperatures and most parts of Australia experienced an exceptionally mild winter.

Maximum temperatures were also well above the national average, with 3.2 degrees above normal, the largest ever recorded in any month.

Dr David Jones, head of climate analysis at the Bureau of Meteorology's national climate centre, said one of the biggest impacts in the last year had been the absence of cold, with a massive decline in sea ice in the Arctic.

"The last six months have been the warmest six months on record for Australia," Dr Jones told reporters in Melbourne today.

"We expect 2009 will be either the second warmest year on record for Australia or the third warmest."

He said the results were not surprising.

"Every decade's been getting warmer for the last 70 years.

"Clearly climate change hasn't stopped, global warming hasn't stopped..."

The outlook for the summer is consistent, Dr Jones said, with warm daytime conditions in northeast Australia forecast to continue.