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:: California Evapotranspiration Data ::


This website offers evapotranspiration data for two purposes: water balances, and irrigation scheduling and design. **For an explanation of the data and calculation methods, please click here.**

 

Step 1.  Select data type (Water Balance or Irrigation Scheduling & Design)

Step 2.  Select irrigation method.  (Surface, Sprinkler, or Drip/Microspray)

Step 3.  Select data format (PDF or Excel Spreadsheet)

Step 4.  Select relative precipitation year.  (1997 Typical Year, 1998 Wet Year, or 1999 Dry Year)

Step 5.  Select an ETo Zone by clicking on an interactive map.

 

The data is available in .pdf or Microsoft Excel spreadsheet form.  The data in either format is exactly the same.   Note:  For the .pdf files, you will need Adobe Acrobat Reader in stalled on your system.  If you do not currently have Acrobat Reader, click here to download a free version.  If you would prefer to access the data as .dif (data interchange format) files, please email mjholman@calpoly.edu.

 

Please note:  The pages linked in the table below use image maps to visually indicate the zone locations.  If you already know the zone you are looking for, or if you are using a screen reader or other assistive technology, please we offer a text-based listing of zones and data for Water Balance values or for Irrigation Scheduling and Design values.

 

 

Monthly ETc used for Water Balances

These evapotranspiration values have been adjusted for decreases in vigor and bare spots.  The estimates by ITRC have concluded a reduction in ETc of approximately 7% (CALFED/ARI Evaporation Study Report).

 

 

Surface Irrigation

PDF Format Excel Format

Typical

Wet

Dry

Typical

Wet

Dry

 
 

Sprinkler Irrigation

PDF Format Excel Format

Typical

Wet

Dry

Typical

Wet

Dry

 
 

Drip/Microspray Irrigation

PDF Format Excel Format

Typical

Wet

Dry

Typical

Wet

Dry

 

Click here for a text-based listing of zones and data for Water Balance values

Monthly ETc used for Irrigation Scheduling and Design

These evapotranspiration values have not been adjusted for bare spots and decreased vigor.  These values are best estimates of evapotranspiration throughout California.

 

 

Surface Irrigation

PDF Format Excel Format

Typical

Wet

Dry

Typical

Wet

Dry

 
 

Sprinkler Irrigation

PDF Format Excel Format

Typical

Wet

Dry

Typical

Wet

Dry

 
 

Drip/Microspray Irrigation

PDF Format Excel Format

Typical

Wet

Dry

Typical

Wet

Dry

 

Click here for a text-based listing of zones and data for Irrigation Scheduling and Design values

 


Additional Helpful Links:
CIMIS data
Transpiration from precipitation
Evaporation from precipitation
ET from precipitation