The annual analysis found the 2000s were warmer than the 1990s, which were warmer than the 1980s, challenging claims that the globe has cooled in recent years.

Only North America had a cooler-than-average year in 2009. Large parts of southern Asia and central Africa are expected to have their hottest year ever.

Arctic sea ice - often at the centre of the debate about global warming - is at its third lowest level since detailed measurement began 30 years ago. The lowest level was in 2007.

''Every summer the amount of Arctic ice is getting very low,'' World Meteorological Organisation secretary-general Michel Jarraud said in Copenhagen.

In Australia, the year was marked by three ''exceptional heatwaves'', including the wilting south-eastern summer that culminated in the Black Saturday bushfires that killed 173 people.

Victoria recorded its highest ever temperature - 48.8 degrees.

Heatwaves were also recorded in the south-east in November and on the subtropical east coast in August.

Winter was exceptionally mild over most of the continent, with maximum temperatures 6 to 7 degrees above average in some places.

Northern Australia, however, recorded a cooler-than-average summer, with some sites recording temperatures be-tween 3 and 4 degrees below average.

The data behind the report was drawn from the various national meteorological and hydrological services of 189 countries.

It was analysed separately by the National Oceanic and Atmospheric Administration in the United States, NASA's Goddard Institute of Space Studies and Britain's Hadley Centre in partnership with the Climatic Research Unit at the University of East Anglia.

A final version of the 2009 weather data will be published in March.