Satellite microwave measurements of sea surface temperature (SST), sea surface wind speed, atmospheric water vapor and cloud liquid water have been analyzed for the three-month period from July to October 1978. During this period the Scanning Multichannel Microwave Radiometer (SMMR) on the Seasat satellite provided continuous orbital coverage of the world's oceans. Monthly contour maps and zonal averages of the SMMR measurements have been produced to examine the consistency of the Seasat data over longer temporal and spatial scales than has hitherto been investigated. With small (∼0.5°C) bias corrections to the SST estimates, the SMMR appears capable of detecting SST anomalies of ≲1°C, except where radio frequency inteference occurs. The SMMR wind speed and water vapor distributions indicate large-scale atmospheric circulation patterns, and provide complete coverage in regions of sparse ship and radiosonde data. The SMMR cloud liquid water measurements show features similar to those observed in measurements of cloud cover by visible and IR sensors, but indicate the greater SMMR sensitivity to liquid rather than ice content. These SMMR results indicate the potential for future use of microwave radiometry in ocean, weather and climate applicationss.