ET-IDWR Stations

This dataset reflects weather station locations in and surrounding the state of Idaho that are available on the ET-IDWR website (https://et-idwr.idaho.gov/). The ET-IDWR website provides estimates of evapotranspiration (ET), net irrigation requirements (NIR), and effective precipitation supporting ET (PEff). These data and this web site were produced in 2007 and were updated in 2009, 2012, 2017, 2023, and 2025. ET calculation procedures employ a modern reference equation (ASCE standardized Penman-Monteith method) and a modern procedure to calculate crop coefficients that considers the impact of surface wetting by irrigation and precipitation on total evaporation from the soil surface. ET is provided for daily, monthly, and annual timesteps for 212 weather station locations across Idaho and adjoining states. In addition to ET and NIR estimates for agricultural crops grown in Idaho, ET estimates are available for a number of native plant systems (wetlands, rangelands, and riparian areas) and open water surfaces. The ET and NIR estimates are intended for use in design and management of irrigation systems, for water rights management and consumptive water right transfers, and for hydrologic studies. ET estimates are available for all times during the calendar year to provide information for land application design, operation, and management of waste streams from agriculture, food processing and other sources during the nongrowing periods. These web pages allow you to access historical ET data for Idaho and adjoining states at various locations. Currently, the data are based on 212 stations associated with five meterological networks. Each station in the list of stations below ends with an abreviation that indicates the meterological network. The five networks are: NWS -- National Weather Service Cooperative Observer Network PN-AM -- USBR Pacific Northwest Region AgriMet Network GP-AM -- USBR Great Plains Region AgriMet Network AM/INL -- USBR Columbia-Pacific Northwest Region AgriMet Network and NOAA INL Center RAWS -- National Interagency Fire Center Remote Automatice Weather Station Network