Last year was our planet's fourth warmest on record, according to data published by NASA this week.

Earth's mean surface temperature during 2018 was 0.83 degrees Celsius warmer than the average of the years between 1951 and 1980, according to NASA.

This puts 2018 behind 2016, 2017 and 2015 as the top four warmest years in records dating back to 1880.

According to analysis by the Bureau of Meteorology, 2018 was also Australia's third warmest year on record based on mean temperature and the second warmest based on average maximum temperatures.

This year has also started on a warm note, with Australia just registering its warmest calendar month on record during January.