Sea surface temperature data from the SEASAT Scanning Multichannel Microwave Radiometer (SMMR) has been maped for the period July 7 to August 6, 1978, in the western North Pacific, 20¿N--50¿N, 140¿E--180¿, and compared against similar maps constructed from all available ship observations. The temperature difference between the SMMR and ship maps has a standard deviation of 0.75¿C, about a mean bias of 0.22¿C, SMMR being warmer. The average standard deviation of all individual observations about the mapped values is 1.51¿C and 2.10¿C for SMMR and ship, respectively. Both the SMMR and ship maps exhibit the known major climatological features for the region. In addition, both data types yield similar maps of sea surface temperature anomaly (departure from climatology), with large-scale (>500 km) anomaly features of 1¿--3¿C. Aside from having a lower noise level, the SMMR data is superior to the ship data for constructing large-scale maps because it is more uniformly distributed in space and time.