Earth has been on a clear warming trend for decades now, and 2019 did nothing to change that.
A year ago came second only to 2016, when temperatures were boosted by the El Niño weather system, in terms of average global temperatures.
The details: The report added that warming has been particularly pronounced during the last five years, and that every decade since the 1960s has been hotter than the last. New records were also set in Germany, the Netherlands, Belgium, Luxembourg and in the United Kingdom at 38.7C.
NASA's temperature analyses incorporate surface temperature measurements from more than 20,000 weather stations, ship- and buoy-based observations of sea surface temperatures, and temperature measurements from Antarctic research stations. It found that the global mean temperature in 2019 was 1.28 °C (2.31 °F) above the average temperature of the late 19th century.
The decade that just ended was by far the hottest ever measured on Earth, capped off by the second-warmest year on record, two USA agencies reported Wednesday.
Differences between the various estimates arise largely from the way that the data-sparse polar regions are handled.
According to NOAA, the past five years have been the hottest five ever, nearly 1.7 degrees (0.9 C) warmer than the average in the 20th century.
Deke Arndt, chief of the global monitoring branch of NOAA's National Centers for Environmental Information, said ocean temperature is an important measure of overall trends because roughly 90% of warming from greenhouse gases in the atmosphere is transferred to the ocean.
"Each decade from the 1980s has been successively warmer than all the decades that came before".
The past five years, and past decade were also the warmest on record in terms of ocean heat content, that study showed.
The Geneva-based WMO combined several datasets, including two from the U.S. space administration NASA and the UK Met Office.
The Bureau of Meteorology in Australia have also recently confirmed that 2019 was the warmest and driest year on record in Australia.
The hottest year on record was 2016, when a recurring El Nino weather pattern pushed the average surface temperature to 1.2C above pre-industrial levels, the WMO said.
Last year was the second-hottest year since records began and extreme weather like the Australian bushfires are more likely in future, the World Meteorological Organization (WMO) says.
"Unfortunately, we expect to see much extreme weather throughout 2020 and the coming decades, fuelled by record levels of heat-trapping greenhouse gases in the atmosphere", he said.
Earth's atmospheric carbon dioxide emissions, a potent greenhouse gas, are now skyrocketing.
Several public figures, including former President Barack Obama and Swedish environmental activist Greta Thunberg, have weighed in on the crisis, urging leaders to seriously address climate change and people to do what they can to help.