The World Meteorological Organization said average temperatures around the world in 2010 were 0.95 degrees Fahrenheit (0.53 Celsius) above the 1961-90 mean that is used for comparison purposes.
"The 2010 data confirm the Earth's significant long-term warming trend," said Michel Jarraud, the agency's top official.
He added that the ten warmest years after records began in 1854 have all occurred since 1998.
WMO's figures are based on data collected by Britain's Meteorological Office, the U.S. National Climatic Data Center and NASA.
Recent warming has been especially strong in Africa, parts of Asia, and parts of the Arctic, the agency said.
Significantly cooler weather was registered mainly toward the end of the year, especially in northern Europe, parts of Russia and in the eastern United States.
The Geneva-based global weather agency also noted that last year's extreme weather - notably the heat wave in Russia and monsoon flooding in Pakistan - has continued into the new year.
It cited heavy floods in Sri Lanka, the Philippines, Brazil and Australia as examples.