January 2017 was the third warmest January in 137 years of modern record-keeping, according to a monthly analysis of global temperatures by scientists at NASA's Goddard Institute for Space Studies (GISS) in New York.
Last month's temperature was 0.20 degrees Celsius cooler than the warmest January in 2016. However, it was 0.92 degrees Celsius warmer than the mean January temperature from 1951-1980.
Two of the three top January temperature anomalies have been during the past two years. 2016 was the hottest on record, at 1.12 degrees Celsius warmer than the January mean temperature, followed by 2007 at 0.96 degrees Celsius warmer. January 2017 placed third.
The monthly analysis by the GISS team is assembled from publicly available data acquired by about 6,300 meteorological stations around the world, ship- and buoy-based instruments measuring sea surface temperature, and Antarctic research stations.
The GISTEMP monthly temperature anomalies superimposed on a 1980-2015 mean seasonal cycle. Credit: NASA/GISS.
The modern global temperature record begins around 1880 because previous observations didn't cover enough of the planet. Monthly analyses are sometimes updated when additional data becomes available, and the results are subject to change.