California Irrigation Management Information System (CIMIS)
has over 125 weather stations throughout the state that
provide hourly data on temperature, wind, humidity,
precipitation and other ET variables. Pictured is Station 6 on
the UC Davis campus. CIMIS is part of the Water Use and
Efficiency Branch of California Department of Water
Resources, Division of Statewide Integrated Water
The first report of the California Almond Sustainability Program, released in 2013, shows that while the vast majority of almond growers employ technology and practices to significantly improve irrigation efficiency, fewer than half are using crop evapotranspiration (ETc) as a calculation for scheduling irrigations.
This can be an especially helpful tool under limited water allocations in which growers can help minimize long-term impact to trees and future crops by applying water as a percent of ETc throughout the growing season in proportion to the percentage of water available.
The Almond Board has developed a section on its website to help growers understand how to use ETc for scheduling irrigations. Another valuable resource is the publication Irrigation Scheduling 101, by Merced County Extension farm advisor David Doll.
Making ET-based calculations requires access to recent and
predictive weather data in a location near the orchard. The California Irrigation Management Information System (CIMIS) has
more than 125 weather stations throughout the state that provide
hourly data on temperature, wind, humidity, precipitation and other ET variables. The Almond Board website mentioned above provides step-by-step instructions for navigating the CIMIS website to help growers find the data near their orchards and perform calculations needed to schedule irrigations according to evapotranspiration rates for almonds.