Surface temperature observations have been used to infer a global warming of about 0.7 ¿K over the last century. Here, we present a new way of deriving temperature trends from observations of mountain surface pressure. From the hydrostatic equation it can be shown that a warming below the mountain increases the local pressure. This signal increases with height. The derived temperature trends from a few sites are consistent with reported regional warmings and a recent acceleration. These results provide independent confirmation of regional warming of the lower troposphere on a longer time scale than is currently available from radiosondes and satellites. ¿ 1999 American Geophysical Union