According to the Copernicus Climate Change Service (C3S), implemented by the European Meteorological Center (ECMWF), 2017 was the third in a series of exceptionally warm years.
Specifically, global average surface air temperature exceeded 14.7 degrees Celsius.
North and south
The 14.7 degrees global average represents approximately 0.1 degrees Celsius cooler than the warmest year recorded, 2016, and one tenth warmer than the second warmest second year, 2015. Comparatively, 2017 was 1.2 degrees Celsius warmer than the pre-industrial value for the 18th century.
Temperatures for 2017 were higher than the 1981-2010 weather average in most regions of the world. These data were obtained by combining millions of meteorological and marine and satellite observations, with models to produce a complete reanalysis of the atmosphere.