The United Nations weather agency says 2014 was the warmest year on record, though the temperature difference with 2010 and 2005 is so small that it's impossible to say for sure which of the three years was the hottest.
The World Meteorological Organization's analysis Monday mirrored findings two weeks ago by NASA and the National Oceanic and Atmospheric Administration, and also included data from the Met Office in Britain.
The Geneva-based WMO said surface temperatures were 0.57 C (1.03 F) above average last year. That's slightly warmer than 2010 and 2005, but the difference was within the uncertainty margin of 0.10 C (0.18 F).
With 14 of the 15 hottest years recorded this century, WMO chief Michel Jarraud said warming is expected to continue as atmospheric levels of heat-trapping CO2 rise.
Japan in January became the first temperature monitoring institution to report 2014's climate data showing that last year was the planet's warmest year since thermometers began monitoring temperatures in the late 19th century.
The Japan Meteorological Agency's preliminary temperature data showed that 2014 exceeded all other data in its records going back to 1891. The annual global average surface temperature anomaly in 2014, according to JMA, was 0.27 degrees Celsius, or 0.48 degrees Fahrenheit, above the 1981-2010 average, JMA said.
Other studies, using data from ice cores, tree rings, corals and other so-called "proxy" data shows the planet has not been this warm in at least 4,000 years, while other data shows that the level of the main global warming gas has not been this high in all of human history.