Abstract:A new sea surface temperature (SST) climatological normals during the 1971-2000 is introduced with reconstructed SST and optimum interpolation (OI) SST from Reynolds and Smith. The new climatological normals will be put into operational use for National Climate Center in 2003. The changes in the SST anomalies and seven SST indices caused by the climatology are analyzed. Furthermore, ENSO episodes since 1950 are defined by NINO3 index derived from Reynolds climatological normals .