The latest data indicate it is likely that the current El Niño has peaked and that while similar to the 1997-98 El Niño, it is not quite as strong either 1997-98 or 1982-83. El Niño is the name used for the warm water part of the El Niño-Southern Oscillation (ENSO) cycle of interaction between the ocean and atmosphere in the central and east equatorial Pacific ocean. Its effects on climate will be felt for several more months in any case as the ocean warmth trails off probably until as late as June.
For all the details and analysis, see Bob Tisdale’s excellent post.