A theoretical relationship is derived to estimate the sea surface skin temperature from near-surface wind speed and the diurnal variation of sea surface bulk (or bucket) temperature. Coefficients in the relation are determined using the R/V Franklin data during the Tropical Ocean-Global Atmosphere (TOGA) Coupled Ocean-Atmosphere Response Experiment (COARE). In contrast to previous methods, surface energy flux data are not explicitly required but rather are implied by the temporal variation of bulk temperature. A multiyear hourly skin temperature data set is obtained using data of bulk temperature at 1-m depth and wind speed from the TOGA Tropical Atmosphere-Ocean (TAO) moored buoys spanning the tropical Pacific Ocean from 95 ¿W in the eastern Pacific to 137 ¿E in the western Pacific between 9 ¿N and 8 ¿S. The diurnal amplitude of skin temperature reaches its maximum of about 2.8 K for daily averaged wind speed between 1--2 m s-1 and skin temperature between 20¿--21 ¿C and decreases with greater wind speeds. The most frequent amplitude is about 0.5 K, the average amplitude is 0.65 K, and the accumulated frequency for amplitudes greater than 1 K is 10% within the parameter space of daily averaged wind speed between 1 and 15 m s-1 and daily averaged skin temperature between 18¿ and 34 ¿C. ¿ 1999 American Geophysical Union