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, Joinfo.com reports with reference to NASA.
A map of the January 2017 LOTI (land-ocean temperature index) anomaly shows that most of North America and Siberia were much warmer than the 1951-1980 base period. Much of the rest of Asia was also relatively warm. Parts of Antarctica are gray because data from stations there had not yet been received.
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 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.