This dataset contains monthly crop irrigation requirement (CIR) values from 1938 through 2014 for six canal service units used in the Lower Rio Grande Basin groundwater flow model (SSPA, 2007). CIR values from 1938 through 2010 were extracted from the New Mexico Office of the State Engineer’s (NMOSE’s) Canal spreadsheet, version 11.2 (Barroll, P., NMOSE, written commun., 2011). CIR values from 2011 through 2014 were copied from a year within the 1938 through 2010 dataset with a similar total annual precipitation as recorded at the State University, NM US station, part of the National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center (NCDC) Global Historical Climatology Network (GHCND) (NCDC, 2016a, b). CIR values are presented in units of acre-feet per acre.