Correction: Corrigendum: Impact of urbanization and land-use change on climate

Nature 423, 528–531 (2003). When calculating areal averages, which involve weighting gridded data with the cosine of the latitude of half-degree grid boxes, we divided the sum by the total number of grids but omitted to divide the sum also by the average cosine latitude of the domain, which is 0.786. This error affects only the area-averaged values, not the maps or the station values, or the relative differences between station and reanalysis values.