A new report containing nearly a century's-worth of air temperature data is available online from the Carbon Dioxide Information Analysis Center (CDIAC). The mean monthly and annual values of surface air temperature were compiled from existing World Weather Records, Monthly Climatic Data for the World, and Meteorological Data for Individual Years over the Northern Hemisphere (excluding the former USSR). These published records were supplemented with information from various national publications. The compiled and updated data series through 1999 shows that the northern hemisphere has warmed at a rate of 0.6 degrees celsius per 100 years, and the southern hemisphere at a rate slightly greater than 0.5 degrees celsius per 100 years. Anomalies in the global record show unprecedented warming in the 1980s and particularly the 1990s. The data, which show global and zonal temperature deviations (seasonal and annual), are available as text or graphics. Visitors to the site can also find citations for articles in which the data were published.