A technique is proposed to estimate sea surface temperature (SST) using dual-frequency microwave data (24 GHz and 31 GHz) to correct infrared (IR) window data for atmospheric absoprtion effects. In the ideal noise-free environment the new method has the same accuracy in SST as the IR split-window method. However, the method using the microwave channels has eight times more tolerance of instrumental noise than the IR split-window method. Hence using the microwave channels yields better SST estimations in the presence of instrumental noise in the radiometers; even in low noise level of the IR radiometer, the combined use of the dual-frequency microwave data with the IR window data improves the accuracy in the estimated SST. ¿ American Geophysical Union 1994