Climate at a Glance
Global temperature anomaly data come from the Global Historical Climatology Network-Monthly (GHCN-M) data set and International Comprehensive Ocean-Atmosphere Data Set (ICOADS), which have data from 1880 to the present. These two datasets are blended into a single product to produce the combined global land and ocean temperature anomalies. The available timeseries of global-scale temperature anomalies are calculated with respect to the 20th century average, while the mapping tool displays global-scale temperature anomalies with respect to the 1981-2010 base period. For more information on these anomalies, please visit Global Surface Temperature Anomalies.