Last year tied with 2005 as the warmest year on record around the world, two US climate agencies say.
The National Climatic Data Center (NCDC) and NASA's Goddard Institute for Space Studies said global surface temperatures in 2010 were 0.62°C above the 20th century average, tying with the record set in 2005.
Many places, such as Russia and Pakistan, suffered from heat waves and floods that killed thousands, scorched crops and inundated countless farm acres.
Those events, caused in part by a shifted jet stream in the atmosphere, helped lead to record global food prices and threaten to trigger food riots such as those seen in 2008.
NCDC chief of the scientific services division David Easterling says the trend of rising temperatures since 2000 increases the possibility of extreme weather such as heat waves, droughts and floods.
Goddard Institute for Space Studies director James Hansen said "if the warming trend continues, as is expected, if greenhouse gases continue to increase, the 2010 record will not stand for long."
Every year since 2000 has ranked as one of the 15 warmest years on record.
In New Zealand, 2010 was the fifth warmest year since 1900.