30-Year Normals

The normals are baseline datasets describing average monthly and annual conditions over the most recent three full decades. They are our most popular datasets. The current PRISM normals cover the period 1981-2010.

Long-term average datasets are modeled with PRISM using a digital elevation model (DEM) as the predictor grid. Given their importance, the normals were subjected to extensive peer review. See PRISM datasets for more information; the data available from this page is "Norm81m" (normals). For information on when the grids were most recently updated, see calendar of PRISM data updates.

PRISM normals are available for certain other regions as well (Virgin Islands, Jamaica, Pacific Islands [including Hawaii]).