With data from just the first nine months, scientists are 90% certain that 2016 will pass the mark set by 2015.
Temperatures from January to September were 1.2C above pre-industrial levels, according to the World Meteorological Organization (WMO).
The body says temperatures should remain high enough for the rest of the year to break the previous record.
El Nino has had an impact, but the most significant factor driving temperatures up continues to be CO2 emissions.
The provisional statement on the status of the global climate in 2016 has been released early this year to help inform negotiators meeting in Morocco, who are trying to push forward with the Paris Climate Agreement.
The document says the year to September was 0.88 above the average for the period between 1961-90, which the WMO uses at its baseline.
The whole of 2015, which broke the previous record by a significant amount, was 0.77 above the 1961-90 average.