An empirical method has been developed for estimation of sea surface temperature (SST) at dawn and noon in local time from microwave observations at other times of the day. By using solar radiation, microwave sea surface wind, and SSTs, root-mean-square differences were reduced to approximately 0.75 and 0.8 °C for dawn and noon, respectively. The pseudo SST variation and spatial patterns found in daily mean SST values by simple averaging of samples were damped down by use of diurnal correction. The satellite SST with the diurnal correction shows highly significant coherent variation with in-situ measurements.