The University of Washington Department of Atmospheric Sciences offers a &Pacific Decadal Oscillation& (PDO) north Pacific SST anomalies dataset. These are updated standardized values for the PDO index derived as the leading PC of monthly SST anomalies in the North Pacific Ocean, poleward of 20N. The monthly mean global average SST anomalies are removed to separate this pattern of variability from any &global warming& signal that may be present in the data.
PDO data are updated every two or three months.
[Summary Adapted from the U. Washington Atmospheric Sciences Department Homepage]