This archive covers two high resolution sea surface temperature (SST) analysis products developed using an optimum interpolation (OI) technique. The analyses have a spatial grid resolution of 0.25 degree and temporal resolution of 1 day. One product uses Advanced Very High Resolution Radiometer (AVHRR) infrared satellite data, while the other uses satellite data from both AVHRR and the Advanced Microwave Scanning Radiometer from NASA Earth Observing System (AMSR-E). Both products also use sea-ice data, in situ data from ships and buoys, and include a large-scale adjustment of satellite biases with respect to the in situ data. Two products are needed because of the increase in signal variance from AMSR-E due to its near all-weather coverage. For both products, the results show improved spatial and temporal resolution compared to heritage weekly 1.0 degree OISST analyses from the NWS NCEP. The AVHRR-only product uses Pathfinder AVHRR data, when available, from September 1981 through December 2005, and operational Navy AVHRR data for 2006 onwards. Pathfinder AVHRR was chosen because of good agreement with the in situ data. The combined AMSR-E and AVHRR product begins with the start of AMSR data in June 2002 and ends in October 2011, when the AMSR-E instrument ceased to function properly. In this second product, the primary AVHRR contribution is in regions near land where AMSR-E is not available. However, in cloud-free regions, use of both infrared and microwave instruments reduces systematic biases because the error characteristics are independent. For both products, in areas where sea ice is present, SST is estimated from sea ice fraction datasets from NASA GSFC before 2005 and then from NWS NCEP from 2005 onwards. Preliminary products are produced daily in near real-time (1-day latency) and may be updated in the first few days if critical input data become available after the initial production time. After two weeks, a complete or final product is generated with no additional changes expected. The preliminary products from near real-time data productions began in October 2008 for Version 2.0.