The global average temperature for the first 10 months of 2018 was 0.98C above the levels between 1850-1900 according to five independently maintained global data sets. Adding to a stretch of five years that are now collectively the hottest period since modern measurements began. This means 2018’s average global temperatures were the fourth warmest since 1880, placing it behind 2015, 2016 and 2017.
The 20 warmest years on record have been in the past 22 years, with the 2015-2018 making up the top four. According to the World Meteorological Organization (WMO) the year 2016 remains the warmest on record. The reason being a particularly strong El Niño, which is a periodic event that warms parts of the Pacific Ocean and influences weather patterns around the world. The factors that slightly cooled 2018 compared to previous years, according to WMO, was the La Niña which is associated with lower than average sea surface temperatures.
Now scientists and researchers claim that a weak El Niño is expected to form in early 2019 which make that year warmer than 2018.
Source: BBC, WMO