Data from all three are used by the World Meteorological Organization (WMO) and formed the basis of its provisional figures in December.
Talking to journalists, Dr Schmidt said the results from the two sets of data showed "a lot of warmth in the oceans".
"It shows very clearly that it has been the warmest year on record in the oceans but it wasn't quite the warmest year in the land records but combined it did give us the warmest year," he explained.