97E06910-16EE-422E-927A-9AC3DBEB69C2 eng utf8 dataset dataset EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development - Center for Public Health and Environmental Assessment (CPHEA), EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas pointOfContact 2025-12-04 ISO 19139 Geographic Information - Metadata - Implementation Specification 2007 2 column 7920 751.283846 row 4269 751.283846 area true false -2950369.144970 115807.214150 -2950369.144970 3323037.952071 2999798.914141 3323037.952071 2999798.914141 115807.214150 24714.884586 1719422.583110 center 102039 Esri 8.1.2 EnviroAtlas - PRISM 30-Year Normal Annual Precipitation and Minimum and Maximum Temperature for the Contiguous US (1991–2020) 2022-12-05 creation 2025-09-29 publication U.S. Environmental Protection Agency (US EPA) originator U.S. EPA Office of Research and Development (ORD) - Center for Public Health and Environmental Assessment (CPHEA) Research Triangle Park, NC publisher mapDigital This annual data was accessed from the PRISM project website (https://prism.oregonstate.edu/normals/) and has a spatial resolution of 30 arcsec (800 m). The three climatic variables included in the dataset are total precipitation (inches), maximum temperature (degrees Fahrenheit), and minimum temperature (degrees Fahrenheit). PRISM Climate Group at Oregon State University used climate observations from monitoring stations and interpolated to a gridded format using the PRISM model (Parameter-elevation Regressions on Independent Slopes Model). Interpolation was trained using a DEM (digital elevation model) to improve performance in mountainous regions. The PRISM temperature data were originally reported in °C but were converted to °F. The PRISM precipitation data were originally reported in millimeters but were converted to inches. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets). From Original Metadata (https://prism.oregonstate.edu/normals/): Abstract: Monthly 30-year "normal" dataset covering the conterminous U.S., averaged over the climatological period 1991–2020. Contains spatially gridded average annual total precipitation and temperature at 4km 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. Purpose: Display and/or analysis requiring spatially distributed annual total precipitation and temperature for the climatological period 1991–2020. Supplementary Information: There are many methods of interpolating climate from monitoring stations to grid points. Some provide estimates of acceptable accuracy in flat terrain, but few have been able to adequately explain the extreme, complex variations in climate that occur in mountainous regions. Significant progress in this area has been achieved through the development of PRISM (Parameter-elevation Regressions on Independent Slopes Model). PRISM is an analytical model that uses point data and an underlying grid such as a digital elevation model (DEM) or a 30 yr climatological average to generate gridded estimates of monthly or annual precipitation and temperature (as well as other climatic parameters). PRISM is well suited to regions with mountainous terrain, because it incorporates a conceptual framework that addresses the spatial scale and pattern of orographic processes. Grids were modeled on a monthly basis. Annual grids were produced by averaging (temperatures, dew point, vapor pressure deficit, and solar radiation) or summing (precipitation) the monthly grids. These gridded normals supersede the 1991–2020 normals produced in October 2021. Improvements over the previous version include more stable adjustments of short-period station data to represent the 1991–2020 period, and additional quality control measures. These EnviroAtlas maps show 30-year normal annual precipitation and minimum and maximum temperature during 1991–2020 for the contiguous US. Temperature is displayed in degrees Fahrenheit (°F) and precipitation is displayed in inches (in). Data sets are based on the Parameter-elevation Regressions on Independent Slopes Model (PRISM) developed by the PRISM Climate Group at Oregon State University (https://prism.oregonstate.edu/normals/; Daly, C., J.I et al. 2015. Mapping atmospheric moisture climatologies across the conterminous United States. PloS ONE 10(10):e0141140.). The overall goal of EnviroAtlas is to employ and develop the best available science to map indicators of ecosystem services production, demand, and drivers for the nation. PRISM Group, Oregon State University, https://prism.oregonstate.edu/normals/, data created Dec 2022, accessed 5 Aug 2025. Daly, C., Halbleib, M., Smith, J.I., Gibson, W.P., Doggett, M.K., Taylor, G.H., Curtis, J., and Pasteris, P.A. 2008. Physiographically-sensitive mapping of temperature and precipitation across the conterminous United States. International Journal of Climatology, 28: 2031-2064. Daly, C., J.I. Smith, and K.V. Olson. 2015. Mapping atmospheric moisture climatologies across the conterminous United States. PloS ONE 10(10):e0141140. doi:10.1371/journal.pone.0141140. PRISM Climate Group, 2013, Descriptions of PRISM Spatial Datasets for the Conterminous United States revised February 2025, Oregon State University Corvallis, Oregon. completed EnviroAtlas Coordinator U.S. Environmental Protection Agency, Office of Research and Development - Center for Public Health and Environmental Assessment (CPHEA), EnviroAtlas Geospatial Data Owner (919) 541-3832 109 T.W. Alexander Drive Research Triangle Park NC 27709 EnviroAtlas@epa.gov https://www.epa.gov/enviroatlas publisher asNeeded Alabama Arizona Arkansas California Colorado Connecticut Delaware Florida Georgia Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas United States Utah Vermont Virginia Washington Washington DC West Virginia Wisconsin Wyoming place EPA Place Names 2015-01-31 publication Climate Ecosystem Environment Hazards Human Impact Modeling Risk Water theme EPA GIS Keyword Thesaurus 2007-11-02 publication 020:072 theme Federal Program Inventory 2013-09-16 publication Ecosystem Services EnviroAtlas Environment Environmental Atlas Human Well-being Sustainability theme User 2022-01-11 publication None. Please check sources, scale, accuracy, currency and other available information. Please confirm that you are using the most recent copy of both data and metadata. Acknowledgement of the EPA would be appreciated. EPA Public Domain License licenseUnrestricted https://edg.epa.gov/EPA_Data_License.html unclassified https://project-open-data.github.io/schema/#accessLevel grid eng utf8 Microsoft Windows 10 Version 10.0 (Build 22631) ; Esri ArcGIS 13.5.0.57366 true -135.918214 -55.490597 19.922246 52.998464 1991-01-01T00:00:00 2020-12-31T00:00:00 PRISM_30_year_normals_maximum_temperature_degF_CONUS_1991_2020.tif: maximum temperature (degrees Fahrenheit) – Annual 30-year "normal" dataset covering the Conterminous US averaged over the climatological period 1991–2020. physicalMeasurement 1 1 Band_1 92.17 20.46 Unified Code of Units of Measure [degF] 32 false false false false false PRISM_30_year_normals_minimum_temperature_degF_CONUS_1991_2020.tif: minimum temperature (degrees Fahrenheit) – Annual 30-year "normal" dataset covering the Conterminous US averaged over the climatological period 1991–2020. physicalMeasurement 1 1 Band_1 74.39 1.89 Unified Code of Units of Measure [degF] 32 false false false false false PRISM_30_year_normals_precipitation_inches_CONUS_1991_2020.tif: total precipitation (inches) – Annual 30-year "normal" dataset covering the Conterminous US averaged over the climatological period 1991–2020. physicalMeasurement 1 1 Band_1 244.53 1.79 Unified Code of Units of Measure [in_us] 32 false false false false false Raster Dataset https://enviroatlas.epa.gov/download/PRISM_30yr_normals_precipitation_inches_CONUS_1991_2020.zip download download https://enviroatlas.epa.gov/download/PRISM_30yr_normals_maximum_temperature_degF_CONUS_1991_2020.zip download download https://enviroatlas.epa.gov/download/PRISM_30yr_normals_minimum_temperature_degF_CONUS_1991_2020.zip download download https://enviroatlas.epa.gov/arcgis/rest/services/PRISM/PRISM_30yr_normals_precipitation_inches_CONUS_1991_2020/ImageServer ESRI:ArcGIS offlineAccess https://enviroatlas.epa.gov/arcgis/rest/services/PRISM/PRISM_30yr_normals_maximum_temperature_degF_CONUS_1991_2020/ImageServer ESRI:ArcGIS offlineAccess https://enviroatlas.epa.gov/arcgis/rest/services/PRISM/PRISM_30yr_normals_minimum_temperature_degF_CONUS_1991_2020/ImageServer ESRI:ArcGIS offlineAccess https://www.epa.gov/enviroatlas/enviroatlas-data information information https://www.epa.gov/enviroatlas information information dataset Tests for integrity have not been performed. EPA National Geospatial Data Policy Features have been reviewed by U.S. EPA EnviroAtlas Project Managers for public release. true Features represented have not been tested for completeness EPA National Geospatial Data Policy Features have been reviewed by U.S. EPA EnviroAtlas Project Managers for public release. true Processing Steps are listed below for the processing of the original PRISM datasets for addition to EnviroAtlas. Annual data were downloaded for all variables (precipitation, minimum temperature, and maximum temperature) from PRISM website: https://prism.oregonstate.edu/normals/ Data download needed for addition to EnviroAtlas. 2025-08-05T00:00:00 Minimum and maximum temperature files were converted from degrees Celsius to degrees Fahrenheit. Precipitation files were converted from millimeters to inches. Data needs to match the convention of imperial units of measurement on EnviroAtlas. 2025-09-25T00:00:00 Rasters were reprojected from their original NAD 1983 projection to a custom Albers Conic Equal Area projection using R programming software and the "terra" package. The CRS used for this projection is as follows: crs('+proj=aea +lat_1=29.5 +lat_2=45.5 +lon_0=-96 +lat_0=23 +x_0=0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m'). We chose to project the PRISM rasters to a CRS that matches other EnviroAtlas layers for CONUS. 2025-09-25T00:00:00 asNeeded 2025-08-07