Ortega-Farias, S.O. Escuela de Agronomia, Facultad de Recursos Naturales, Unversidad de Talca, Casilla 747-Talca, ChileA study was performed to evaluate the bulk aerodynamic method for estimating daytime variation of sensible heat flux (HA) for a wetted and non-wetted grass canopy under clear and cloudy days. The aerodynamic resistance applied was corrected for atmospheric stability using the Oregon State University One-Dimensional Planetary Boundary Layer model stability function. The performance of the bulk aerodynamic method was tested with indirect measurements of sensible heat flux (HB) derived from the Bowen ratio energy balance method on 20-min time intervals. Results indicate that there was a good agreement between HB and HA with a coefficient of correlation of 0.93 and slope of the regression line through the origin of 0.96.