September-October-November: 2.1
October-November-December: 2.2
November-December-January: 2.3
December-January-February: 2.2
January-February-March: 2.0
The very strong El Nino of 1997-98 had five consecutive periods measuring an average of 2.18, the 1982-83 just three measuring an average of 2.1.
The current episode is twelve months long (average 1.53), the '97-'98 was thirteen (average 1.56), and the '82-'83 was fifteen (average 1.30).
