This year is set to be the 10th warmest on record despite weather patterns which cool global temperatures, meteorologists have said.
Climate researchers in the UK said 2011 was near the top of records dating back to 1850 despite a "strong and persistent" La Nina weather system in the Pacific which tends to lead to lower temperatures across the world.
The World Meteorological Organisation (WMO) released the figures as countries meet in Durban, South Africa, for the latest UN talks on agreeing a deal to tackle climate change. It said 2011 was the warmest on record for a La Nina year.
The WMO, which bases its figures on three independent data sets from the UK and the US, put the global average temperature at 0.41C above the 1961 to 1990 average of 14C, making it the 10th warmest on record. It said the 13 warmest years on record all occurred between 1997 and 2011.
The Met Office and the University of East Anglia, which maintain one of the three records of global temperatures, said their figures - which put the year in 11th place - showed a continued long-term warming trend in the global climate.
Their data set shows the average global temperature for January to October 2011 was 14.36C, 0.36C above the 1961 to 1990 long-term average of 14C.
According to the Met Office and UEA researchers, each decade since the 1950s has been warmer than the previous decade, and last year was one of warmest on record.
Brian Hoskins, director of the Grantham Institute for Climate Change at Imperial College London and professor of meteorology at Reading University, said: "What we've seen in the science is not one huge change but a number of things - the melting of the ice sheets, the permafrosts and release of methane and the carbon cycle - have tended towards this problem being more serious rather than less."
As negotiators meet in Durban to discuss efforts to tackle climate change, he said it was important to get a global deal on curbing greenhouse gases that would see emissions peak around 2020 and begin to fall by around 3% a year.
Kelly Dent, policy adviser for Oxfam, said: "From flooding in south-east Asia, which killed more than 1,100 people and helped send the price of rice in Vietnam up 30%, to record heat and droughts in the US that crippled agricultural production, extreme weather and rising temperatures was a menace to vulnerable people around the world. This provides a stark reminder of what is at stake in the Durban negotiations."