See the PRISM terms of use for details.

See the PRISM terms of use, which includes an example citation.

As of October 2025, all PRISM raster datasets are made available in Cloud Optimized GeoTIFF (COG) format. Additional raster formats such as NetCDF and BIL are available via our web services. Please see our data formats page for more information.

The Cloud Optimized GeoTIFF (COG) format is a standard GeoTIFF raster that is optimized for web/cloud usage. Please see our data formats page for information about how we distribute PRISM raster datasets in COG format.

PRISM dataset values are stored in standard metric units. Precipitation units are in millimeters and temperature units are in degrees Celsius. Note that when creating PRISM map graphics, we convert data values to inches and degrees Fahrenheit, since most users want to view maps in those units. Solar radiation datasets use units of megajoules per square meter per day, as described in most standard texts.

Each .zip file contains the PRISM grid you selected, plus ancillary files such as metadata, projection information, grid statistics, and internal PRISM information. See our data formats page for more information.

The native grid resolution of the PRISM datasets is 800m. PRISM 4km resolution data has always been available for free to the public. As of March 2025, we also made the PRISM 800m data available for free to the public. PRISM 800m data can be retrieved on our time series data web page, and also via FTP and web services. We still pr , but they have been filtered to 4km resolution for easier downloading and manipulation on this website. The 800m versions of all PRISM datasets, which contain 25x more information, are available to users for a fee. See PRISM Data Sales for details on availability, pricing and ordering.

An FGDC-compliant .xml metadata file is included in every downloaded .zip package.

The PRISM Data Explorer is a powerful web-based tool that allows you to retrieve time series data across spans of days, months, or years very quickly, for any point in the country. We also offer a bulk download option that allows up to 500 points to be returned in a single request.

In addition to this website, we make all PRISM datasets available via FTP and web services. Using a standard FTP client such as FileZilla, you can quickly and easily download multiple years of PRISM data in one operation. Our web services are well suited for automating the retrieval of PRISM datasets on a recurring basis. Please view our bulk download documentation for more information.

PRISM datasets are remodeled and reproduced multiple times within a rolling 6-month window, in order to incorporate as many weather station observations as possible. Our data update calendars provide detailed up-to-date information about PRISM dataset processing of both daily and monthly datasets. Also, the *.info.txt file contained in each .zip package includes pertinent information about grid processing and status.

Yes. See our Supporting Datasets page for the 4km and 800m DEMs used by PRISM.

A station inventory is included in every .zip package (look for the *.stn.csv file). This inventory includes station ID, name, latitude, longitude, elevation, and network abbreviation (we are not permitted to re-distribute the actual data from these stations). Descriptions of the networks we use and their abbreviations are included in our PRISM Datasets document.

PRISM-related publications are available and include download links to PDF versions of the journal articles. Journal articles describing PRISM methods and the PRISM model are recommended.

PRISM normals are available for Alaska, Hawaii/US Pacific Islands, Puerto Rico, US Virgin Islands, Jamaica, and western Canada -- see our Projects page. As of 2025, the PRISM Group is working on modeling and producing both normals and time series data for Alaska (800m and 4km), Hawaii (400m), and Puerto Rico (400m). These datasets will be made available as they are produced.

PRISM produces the USDA Plant Hardiness Zone Map with support from USDA-ARS. The current version of the PHZM was completed in 2023 and is available on the USDA Plant Hardiness Zone Map website. We host the related spatial datasets that we produced on our 2023 USDA Plant Hardiness Zone GIS Datasets web page.

Our gallery of state mean annual precipitation maps provides downloadable map graphics at 150 dpi and 300 dpi. Also, a high resolution version of every map graphic on the 30-year Normals and Time Series Data pages is available for download.

Yes! Information on joining citizen science observing networks (CoCoRaHS and PVOutput) that help improve PRISM data can be found on our Participate in Citizen Science page.

PRISM datasets are remodeled and reproduced multiple times within a rolling 6-month window (8x for daily data, 7x for monthly data), in order to incorporate as many weather station observations as possible. These versions are not kept -- each time a PRISM dataset is reproduced, the older version is overwritten. The "grid count" integer can be used to determine the version of a particular PRISM dataset. This integer value can be found in the *.info.txt file in every .zip package, and can also be retrieved via our gridCount web service.

We do retain prior versions of daily and monthly data after an entire variable (i.e., precipitation) is remodeled, for all years. We also retain prior versions of 30-year normals, which are available by request.

Yes. We provide PRISM polygon "mesh" GIS layers in Esri shapefile format. Both 4km and 800m polygon mesh layers can be found on our Supporting Datasets page.

Yes. In 2025 we implemented a map graphics archive, which contains map graphics for every PRISM time series grid and normals grid, as well as several other categories of map graphics (i.e., month-to-date, anomalies, etc.). All PRISM map graphics are recreated every time a grid is reproduced, so the map graphics are always based on the latest PRISM data. The map graphics archive is available via FTP as well.