The CIMIS Web API was released to production on December 17th, 2012. We are excited to offer CIMIS data to the public free of charge via a web Application Programming Interface (API). The CIMIS Web API is the production realization and extension of the former ET-XML Web Services.

The CIMIS Web API is managed by the California Department of Water Resources (DWR). The ET-XML Web Services was a separately developed project, funded by a DWR grant that has been integrated into the CIMIS Web API and supported by DWR. Irvine Ranch Water District was the lead agency on the ET-XML grant funded project.

The CIMIS Web API delivers data over the REST protocol from an enterprise production platform. The system provides reference evapotranspiration (ETo) and weather data from the CIMIS Weather Station Network and the Spatial CIMIS System. Spatial CIMIS provides daily maps of ETo and solar radiation (Rs) data at 2-km grid by coupling remotely sensed satellite data with point measurements from the CIMIS weather stations.

  • The CIMIS Weather Station Network supports more than 140 active stations randomly located throughout the state of California.
  • The Spatial CIMIS System provides statewide ETo and Rs data and averaged ETo by zip-codes.

The RESTful HTTP services reach a broader range of clients; including Wi-Fi aware irrigation smart controllers as well as browser and mobile applications, all while expanding the delivery options by providing data in either JSON or XML formats.

The new CIMIS Web API expands on the services provided by its predecessor with greater ease of use. The RESTful services have been designed with a simplified interface that allows data to be queried by specific weather stations, zip codes, geographic coordinates, and even street addresses. New services allow users to get CIMIS weather station information as well a comprehensive list of supported zip codes for the spatial and weather station systems.

The following webinar video was taken on November 8th, 2012 during the beta test kickoff meeting.