Monthly 30-year "normal" dataset covering the Susquehanna River Basin, averaged over the climatological period 1991-2020. Contains spatially gridded average total precipitation at 800m grid cell resolution. Distribution of the point measurements to the spatial grid was accomplished using the PRISM model, developed and applied by Dr. Christopher Daly of the PRISM Climate Group at Oregon State University. This dataset is available free-of-charge on the PRISM website.