You can find the data you are looking for in the following dataset:
/SOURCES/.NOAA/.NCEP/.EMC/.CMB/.GLOBAL/.Reyn_SmithOIv2/
This dataset of SSTs and SSTAs is kept up to date monthly and includes a recent climatology for 1971-2000. The data are also interpolated to a 1 x 1 degree lat/lon resolution. You can click on "climatology" and then "Climatological Sea Surface Temperature" to see the monthly climatology. Or click on "monthly" and then "Sea Surface Temperature" to see the SSTs or "Sea Surface Temperature Anomaly" to see the anomalies from the 1971-2000 average.
-- Michael Bell