So it all boils down to how https://www.ncei.noaa.gov/products/optimum-interpolation-sst https://www.ncei.noaa.gov/products/optimum-interpolation-sst is created

So it all boils down to how https://www.ncei.noaa.gov/products/optimum-interpolation-sst https://www.ncei.noaa.gov/products/optimum-interpolation-sst is created. The NOAA 1/4° Daily Optimum Interpolation Sea Surface Temperature (OISST) is a long term Climate Data Record that incorporates observations from different platforms (satellites, ships, buoys and Argo floats) into a regular global grid. The dataset is interpolated to fill gaps on the grid and create a spatially complete map of sea surface temperature. Satellite and ship observations are referenced to buoys to compensate for platform differences and sensor biases.