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The crop coefficient (Kc) values of rice paddy are important for estimating accurate rice crop evapotranspiration (ETc), water transfers planning, efficient irrigation management, and hydrological studies. In this study, ETc was measured and a generalized Kc curve was calculated for paddy rice in the Sacramento Valley, California. Field experiments were conducted in three rice paddy fields during the 2011-2013 growing seasons. Surface renewal analysis, after calibration using eddy covariance method, was applied to obtain sensible heat flux values from high-frequency temperature readings; latent heat flux densities were characterized by the residual of the energy balance method. The results revealed that there is considerable variability in rice water use both spatially and temporally. The average 3-year measured seasonal ETc of the experimental fields ranged from 690 to 762 mm in Butte County and from 681 to 813 mm in the Colusa County. A mean daily seasonal Tc of 5.3 mmd-1 and midseason Tc of 5.8 mmd-1 was observed. The rice Kc values were lower than those commonly used to estimate rice Tc during the midseason and were greater than expected during early growth before canopy closure. For a typical growing season of 145 days, the Kc values were estimated as 1.10, 1.00, and 0.80 for the initial-growth, midseason, and late-season stages, respectively. The generalized Kc curve is quite accurate for practical application and enables growers to determine rice crop water use in a reliable, usable, and affordable format. The proposed Kc information can be used to refine the estimates of rice consumptive water use in the Sacramento Valley for the purpose of water transfers to water-short areas of the State. These Kc values are likely applicable to other locations having similar climate to the Sacramento Valley in California. [ABSTRACT FROM AUTHOR]