This data set consists of four images showing seasonal sea surface temperature (SST) averages for the entire earth. Data for the years 1985-2001 are averaged to produce each seasonal image. The seasons are January-March (sst001i4km.tif), April-June (sst002i4km.tif), July-September (sst003i4km.tif), and October-December (sst004i4km.tif). These SST data are the result of the 4 km Pathfinder effort at the National Oceanic and Atmospheric Administration (NOAA) National Oceanographic Data Center (NODC) and the University of Miami's Rosenstiel School of Marine and Atmospheric Science (RSMAS), which uses data from the NOAA-9, NOAA-11, NOAA-14, and NOAA-16 satellites. The 4 km Pathfinder effort at NODC is an improvement to the original Pathfinder program, which was jointly developed by the National Aeronautics and Space Administration (NASA) and NOAA to provide long-term, consistently calibrated global change data sets to Earth scientists. One of the data sets selected for the Pathfinder project was collected by the Advanced Very High Resolution Radiometer (AVHRR), a scanning radiometer flying onboard polar orbiters operated by NOAA. The original AVHRR Pathfinder Program involved four separate elements: Atmosphere, Land, Oceans, and Calibration. The objective of the AVHRR Oceans Pathfinder was to develop a long and consistent time series of global sea surface temperature (SST) fields. The Pathfinder Project at NODC carries on this objective. The files for each season, also known as seasonal climatologies, are available both as 16-bit (pixel values from 0 to 65535) Hierarchical Data Format (.HDF) data files and as 8-bit (pixel values from 0 to 255) GeoTIFF images. This data set is also referred to as 4 km NODC/RSMAS AVHRR Pathfinder v.5.0 Seasonal Climatologies (1985-2001).