Next past The result of the relationship between the Nino 3,Nino 3.4 SST index and the standardized PC of September, October and November (SON) at various lag times. shown in this table. The highest correlation of 0.43886 and 0.48063 indicates that the Niño3 and Niño 3.4 SST index leads the standardized PC values by 6 month.