What's new at PRISM
right What does "PRISM" stand for?
PRISM stands for Parameter-elevation Regressions on Independent Slopes Model. Our Documents and Publications page includes scientific papers describing the development and use of PRISM.
right What are the terms of use for this data?
See PRISM terms of use for details.
right How should I cite the use of PRISM data or maps?
See PRISM terms of use for details.
right What data formats are available?
PRISM datasets are provided in BIL format (raster data with floating-point numbers) and ASCII GRID format (30-yr normals only). ArcGIS and most other geospatial or data integration tools can read/import BIL. If you need some other format, BIL can be converted using GDAL's format translator (GDAL is an open-source library), among other tools.
right What is a BIL file and how do I use it?
BIL is a standard raster data format widely used in climatology. For details on how to use it, see PRISM Data Formats. Additional information on the BIL raster format specification appears on Esri's ArcGIS Resource Center Raster Data page.
right What units are the data values in?
Dataset values are stored in the standard metric units used for climatology. Precipitation uses millimeters and temperature are in degrees Celsius; in creating map graphics, we convert those values to inches and degrees Fahrenheit for you, since most users want maps in those units. Solar radiation uses megajoules per square meter per day, as described in standard texts (e.g., Crop Evapotranspiration - Guidelines for Computing Crop Water Requirements).
right What data are contained in the downloaded zip files?
Each zip file contains the dataset(s) you selected, plus the associated metadata; see PRISM Data Formats for a detailed list.
right How can I access high-resolution PRISM data?
The native grid resolution of the PRISM datasets is 800m, 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.
right Where is the metadata for datasets?
A metadata file in XML format is included with raster dataset as part of the download package. You can also view or download the metadata directly by using the button available on each data selection page.
right How do I download time series data for individual locations?
Use the Data Explorer tool, which is available via the Explorer tab as well as the homepage.
right How can I download datasets in bulk?
Bulk downloads can be accomplished via FTP or Web Services.
right When was the data last updated?
Check the Data Update Calendar for the latest information.
right Can I obtain the elevations used by the PRISM model in creating maps?
The elevations are available in map and grid form on the Normals page.
right Can I obtain the station observations used to create the maps?
A station inventory is included in every data package as a CSV file. The 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 the PRISM Datasets documentation.
right Where can I read more about the PRISM model and related research?
See the list of Publications about PRISM.
right Are there PRISM datasets outside the conterminous US?
PRISM normals are available for Alaska, Hawaii and US Pacific Island possessions, Puerto Rico, US Virgin Islands, Jamaica, and western Canada from the Projects page. These datasets are the result of specific projects and are not likely to be updated.
right Where can I download digital data for the USDA Plant Hardiness Zone Map?
Digital plant hardiness data can be downloaded from the Projects page.
right Where can I find print-quality map images?
A gallery of state mean annual precipitation maps suitable for printing is available from the Projects page.
right How can I improve PRISM data by participating in a citizen science observing network?
Information on joining citizen science observing networks that help improve PRISM data can be found on the Participate in Citizen Science page.