The comparison of ETo estimates was done based on the weekly averages of PET using correlation coefficient and regression methods through different empirical methods namely Modified Penman, Blaney criddle, Christiansen, Thornthwaite, OpenPan, FAO penman method by using daily weather data for the period 1981-2012 (32 years) has collected for three stations of Chhatisgarh state. | Comparison of the PET values with the open pan evaporation and computation of crop coefficients