This file area contains 30-arc-second (~800-m) resolution 1981-2010 PRISM 30-year climate normals datasets in the following gridded (raster) GIS data formats:

 1) BIL (.bil) - Band Interleaved by Line generic raster format
 2) ASCII GRID (.asc) - ArcInfo ASCII GRID raster format

In the filename, "01" = January, "02" = February, and so on. "14" is the Annual dataset.

To download all .bil or .asc grids at once, select the matching "all_files" .zip file.