Global mean surface air temperature measurements have been derived daily for the period between 1850-2015 based on combined information from satellite and in-situ data sources. This data has been derived using a statistical method to estimate air temperatures at all places and times. It takes into account uncertainty in the input data sets covering errors in the in situ measurements, land station homogenisation and errors in the air temperatures estimated from satellite data . Although the statistical model estimates temperatures at all locations, the product is not globally complete, as areas with too few data to provide a reliable air temperature estimate have been masked out. The derivation of this dataset and the statistical model used has been described further in the EUSTACE Scientific and Product User Guides.