Here's an update to the world's temperature compared to the 1997-8 massive El Nino:
Even though the Nino3.4 anomaly hasn't reached an El Nino phase yet (5 consecutive months of an anomaly above 0.5 C are rquired to be an "official" El Nino), last years's index has been much below that of the big 1997-98 El Nino.
But temperatures have been running higher. Significantly higher.
So in less than 20 years, the warming that resulted from a huge El Nino is now seen from a weak-to-nonexistent El Nino.