Select the calendar on the right to see daily ETo or Solar Radiation maps of California based on Spatial CIMIS data. To retrieve and schedule Spatial CIMIS data, please register, log in, and click on the Spatial Report or Schedule Spatial Report tabs above. Spatial data are available back to 2003.

Spatial CIMIS Solar Radiation maps are generated from remotely sensed satellite data from the Geostationary Operational Environmental Satellites (GOES) using the Heliosat-II model. Solar radiation in this map represents the global horizontal incident solar irradiance. See the Spatial Overview for more details.

Spatial CIMIS ETo Maps are generated by coupling remotely sensed satellite data from the Geostationary Operational Environmental Satellites (GOES) with interpolated CIMIS station data and using the standardized American Society of Civil Engineers Penman-Monteith equation to calculate ETo at 2-km spatial resolution. See the Spatial Overview tab above for more details.

The ETo Zones Map allows users to view the reference evapotranspiration (ETo) Zones for the State of California. The map was developed by DWR and UC Davis and divides the State into 18 zones based on long-term monthly average ETo. The ETo values were calculated using data from various data sources including CIMIS weather stations that had at least five years of archived data. This map can also be viewed and/or downloaded as a PDF document using this link.