Something unusual is happening in the tropical Pacific.
The latest CCSR/IRI ENSO forecast, released August 19, shows an exceptionally strong El Niño developing. But one number really stands out:
+3°C.
Niño-3.4 reached +2.03°C in July, while the latest weekly value, centered on August 12, reached +2.7°C. Meanwhile, a large reservoir of unusually warm water remains beneath the central and eastern Pacific.
So the question is no longer simply whether El Niño will continue.
How strong could it become?
The +3°C signal
The IRI forecast uses 26 models to look ahead. For October–December 2026, 25 of 26 models project Niño-3.4 at or above +2°C.
More strikingly, 15 models reach or exceed +3°C.
The IRI’s standard intensity classification tops out at +2°C. So +3°C would take this event well beyond the highest defined category.
That does not mean +3°C is guaranteed. It means a substantial part of the model ensemble is now exploring that possibility.
What happens next?
A very strong El Niño does not mean equally strong impacts everywhere. ENSO changes the odds of climate outcomes, while regional impacts depend on atmospheric circulation, season, geography, and other climate variability.
So I will be watching the ocean–atmosphere response: Does the warming continue? Does atmospheric coupling strengthen? And how does this extraordinary ENSO signal translate into regional climate patterns?