An effort to update the PRISM 1961-90 mean monthly temperature maps for the United States to the 1971-2000 period is now underway. Maximum and minimum temperature maps for the western United States are presented here. The updated maps reflect several improvements over the 1961-90 versions: (1) grid resolution has been increased from 2.5 min (~4 km) to 30 sec (~0.8 km), (2) extensive data from the RAWS network have been incorporated, (3) mean temperatures for stations with short periods of record have been adjusted to the 1971-2000 period, (4) a high-resolution coastal trajectory model has been used to improve depictions of complex coastal temperature gradients, and (5) the latest version of PRISM was used. Features captured in the maps include coastal effects, elevational influences, temperature inversions, and others. These maps are being used as the predictor grids for PRISM in a new probabilistic spatial QC system being developed for USDA-NRCS Snotel observations. These maps are also the basis for the product expected to be developed through the WestMap climate mapping initiative, which aims to produce a monthly time series of very high-resolution, high-quality monthly climate grids for the western US, with accompanying error assesment statistics.