The Earth's temperature reached its hottest levels since 1880 as 2016 broke records previously set in 2015 and 2014.
Data independently analysed by NASA and the National Oceanic and Atmospheric Administration (NOAA) revealed the average temperature globally increased by 0.99°C in 2016.
NASA estimates it was the warmest year with greater than 95% certainty, taking into account changes in weather station locations and measurement practices.
"2016 is remarkably the third record year in a row in this series," said Gavin Schmidt, NASA's Goddard Institute for Space Studies (GISS) director. "We don't expect record years every year, but the ongoing long-term warming trend is clear."
Findings from the World Meteorological Organization and the UK Met Office, also published today, supported the claim 2016 was the hottest year on record.
Australia recorded its fourth warmest year on record, according to research revealed by the Australian Bureau of Meteorology, at 0.87°C more than the annual national mean temperature.
The global average rise was likely influenced by a strong El Nino, which is said to have influenced Australia's climate at the beginning of the year before breaking down in autumn.
Eight of the 12 months making up the year were the warmest on record.
Weather temperatures have increased by 1.1°C since the late 19th century, says NASA, a change driven by an increased reliance on fossil fuels.
Most of the warming has happened in the last 35 years. Of the 17 warmest years on record, 16 of them have occurred since 2001.