A method is described for correcting air minus canopy temperature differential (Td) for rapidly changing solar radiation (SR). Rapid changes in SR occurred under partly cloudy skies. Td requires about 100 seconds to come to a new equilibrium resulting from the changes in SR. By adjusting measured Td values for nonequilibrium conditions and selecting a reference SR to use for comparisons, it is possible to reduce the standard deviation of Td values to about 1/4 of that of the measured data.