Recent Temperature Variations in Austral South America

A group of 38 surface temperature continuous records in austral South America (latitude hiqher than 20QS) are produced through homogenization and gap filling techniques applied to monthly mean values. Smoothed versions are obtained by an exponential filter. Subregions are determined with similar general temperature trends for the common record between 1931-1987. Warming dominates in Northern Chile. Eastern Central Argentina and latitudes higher than 50QS. Cooling prevails in Central Chile and Northern Argentina. Seasonal PC analysis defines four patterns that explain about 75% of the variance. The longest temperature series belong to large cities where urban growth produces large warming rates.