2017 was the third warmest year on record (since 1880) and the warmest year on record without an El Nino event according to NOAA’s newly released annual climate summary. The Japan Meteorological Agency also concluded that 2017 was the third warmest year on record. NASA, however, ranked 2017 as the second warmest year on record, just ahead of 2015 and behind 2016. Each agency uses slightly different analysis techniques which can lead to small differences in ranking results. Regardless of the technique used, 2017 was ranked in the top 3 warmest years of all time.
Dr. Jeff Masters of Weather Underground gives a good summary of the 2017 climatic events that can be found here.