Analyzed Foundation, Microwave + InfraRed Optimally Interpolated, Near Real Time, Global, Sea Surface Temperature data. The through-cloud capabilities of microwave radiometers provide a valuable picture of global sea surface temperature (SST). To utilize this, scientists at Remote Sensing Systems have calculated a daily, Optimally Interpolated (OI) SST product at quarter degree (~25 kilometer) resolution. This product is ideal for research activities in which a complete, daily SST map is more desirable than one with missing data due to orbital gaps or environmental conditions precluding SST retrieval. Improved global daily NRT SSTs should be useful for a wide range of scientific and operational activities. The addition of SST derived from Infrared (IR) measurements allows higher spatial resolution, and SST near land. However, IR input is less accurate than MW due to cloud contamination. Blending MW and IR enables greater coverage and higher accuracy than IR only SSTs, but current OI does not completely eliminate cloud contamination inherent to IR SSTs. This is a near real time data set and is intended for use in operations applications. A higher-quality "Science Quality" data set is generally available about 10 days after the production of the real time version. It is recommended that the "Science Quality" data be used for scientific applications.