According to a NASA study that looked at the average surface temperature of the planet since 1880, the global temperature of 2018 was 0.83 degrees Celsius warmer than the global temperature in the period from 1951 to 1980.
The last 5 years have been the hottest since the 19th century. It is noteworthy that since that time the global average temperature has increased by 1 degree celsius.
This does not necessarily mean that the entire region of the blue giant has increased. Climate dynamics usually affect segmented regions and not the entire planet at one time.
It is not yet known if 2019 will reach the top 5. But it is likely.
Read the original story: https://climate.nasa.gov/news/2841/2018-fourth-warmest-year-in-continued-warming-trend-according-to-nasa-noaa/