Route 02 · ENSO Stripes
Eighty-six years of the Pacific, one stripe a month.
Red months are El Niño-like and blue months La Niña-like. The deeper the colour, the stronger. The pattern is a rhythm rather than a series of isolated events: long warm spells, cold spells that come back two and three years running, and a warm stripe at the right-hand edge darker than almost anything before it.
ENSO Stripes
Every event since 1950
From NOAA's ONIThe event catalogue
NOAA's episode rule: the three-month Niño-3.4 index (ONI) at +0.5 °C or warmer (El Niño) or −0.5 °C or colder (La Niña) for at least five overlapping seasons. Integrated intensity adds up the index over the whole episode, the ENSO equivalent of a hurricane season's ACE, so a long moderate event can outweigh a short sharp one.
| Event | Peak (ONI) | Class | Seasons | Integrated | Rank | Flavour (DJF) |
|---|
Flavour: DJF Niño-3 against Niño-4 (ERSSTv5). EP = warmth centred in the eastern Pacific, CP = central Pacific. Classes follow the peak three-month value: 0.5 weak · 1.0 moderate · 1.5 strong · 2.0 very strong. The ongoing event is provisional until it has five seasons.