This page contains a list of known issues with PRISM time series and normals datasets.

For detailed information about PRISM dataset versions, please review our PRISM datasets document.

PRISM Time Series Datasets

	Posted	Variable	Period	Location	Issue	Cause	Status
1	12/08/21	ppt	Dec 1951, Jan 1957	Area around Crested Butte, Colorado (-109.97, 38.87)	Monthly precipitation values are about 50% low	Erroneous QC omission of unusually high precipitation observed at Crested Butte	Unresolved
2	03/25/22	ppt	04 May 2012	Extreme north-central Iowa (-94.1, 43.3)	Local precipitation maximum should be ~90 mm, rather than ~300 mm	Station data was reported on the wrong day and conflicted with radar returns	Resolved
3	02/24/25	tdmean	1895-2020	CONUS	Monthly tdmean grids were found to be systematically 0.5-1.0° too low	Erroneous internal post-processing script	Resolved
4	09/15/25	ppt	Jan-Aug 2025	CONUS	Stations were inadvertently dropped from monthly and daily analyses	Database error	Resolved

PRISM Normals Datasets

	Posted	Type	Variable	Period	Location	Issue	Cause	Status
1	12/07/21	Monthly, Annual	ppt	July	Small area (~10x10 km) in central Colorado centered on -105.41, 39.64	Precipitation values are about 25 mm too high	Unstable adjustment of a station with a short period of record	Resolved
2	02/01/24	Monthly, Annual	tmin, tmax, tmean, tdmean, vpdmin, vpdmax	All	Multiple	Small number of West Coast grid cells incorrect	Misalignment with the recently developed daily normals	Resolved
3	08/06/24	Daily	ppt, vpdmin	ppt: Jun 01 - Sep 01; vpdmin: all days	Multiple, most noticeable near Stockton, CA	Small clusters of grid cells missing values	Rounding issue produced small negative numbers instead of zeros in some grid cells	Resolved