The data sets available on this web site were created using the PRISM (Parameter-elevation Regressions on Independent Slopes Model) climate mapping system, developed by Dr. Christopher Daly, PRISM Group director. PRISM is a unique knowledge-based system that uses point measurements of precipitation, temperature, and other climatic factors to produce continuous, digital grid estimates of monthly, yearly, and event-based climatic parameters. Continuously updated, this unique analytical tool incorporates point data, a digital elevation model, and expert knowledge of complex climatic extremes, including rain shadows, coastal effects, and temperature inversions. PRISM data sets are recognized world-wide as the highest-quality spatial climate data sets currently available. PRISM is the USDA's official climatological data.

Important notice:

PRISM data sets were developed through projects funded partly by the USDA Natural Resources Conservation Service, USDA Forest Service, NOAA Office of Global Programs, and others. However, there is little operational funding for maintaining and updating or expanding the data sets. Data are provided as a public service for a limited time. If you find them valuable, please consider doing your part to support the PRISM Group. Contact us for details at 541-737-2531.

Use this site to access up-to-date and historical monthly climate data sets and graphics for the US, explore our data online with our Internet Map Server, view related papers and presentations, or contact us.