El Niño forecast: where the official outlook stands
- Forecast peak
- Oct–Dec 2026
- ~97% odds conditions persist into early spring 2027
- CPC outlook of September 10, 2026
- How strong
- over 90% very strong
- at least +2.0°C · 75% odds of the strongest since 1950
- CPC outlook of September 10, 2026
- Right now
- +3.1°C
- weekly Niño 3.4, week of September 23, 2026 · very strong
The short version of the current El Niño forecast: El Niño Advisory is in effect, RONI — NOAA's official relative ENSO index — reads +1.4°C for JJA 2026, the conventional weekly Niño 3.4 anomaly is running at +3.1°C for the week centered September 23, 2026, and el niño conditions are present and strengthening. Official probabilities and every monthly update we've published since are below; the always-current numbers live on the dashboard, and every source behind them is documented on the data & methodology page.
The official CPC/IRI probability outlook
NOAA's Climate Prediction Center and the IRI issue a joint ENSO outlook around the second Thursday of each month, expressed as probabilities rather than a single prediction — the honest way to forecast a system with real uncertainty. As of the September 10, 2026 outlook: over 90% chance of a very strong event (a peak of at least +2.0°C). Model consensus centers the peak on Oct–Dec 2026. CPC also gives 75% odds of a historic event for October-December 2026 — one exceeding every El Niño back to 1950, defined as +2.5°C or more on the three-month RONI.
Two honesties about those numbers. CPC stated the very-strong figure as a bound — "greater than" — not a point estimate, so the real odds are higher than the number above, not equal to it. And the 97% odds of El Niño persisting into early spring 2027 come from the July 9, 2026 discussion — CPC did not restate persistence this month, and we would rather say so than present an older figure as current.
Official ENSO outlook probabilities
Chance of each state by overlapping three-month season · outlook of 2026-09-10
100% El Niño for the OND 2026 peak season
These are probabilities, not certainties — treat them as the current best odds, due to be revised at next month's outlook. See the 2026–27 event page for the full timeline and what strong-to-very-strong intensity has meant in past events.
What +1.4°C RONI means right now
RONI carries its own ±0.5°C thresholds — the same numbers as the conventional scale, just applied to the ocean's warmth relative to the wider tropics rather than to a fixed climatology. On that scale, +1.4°C for JJA 2026 reads moderate. The conventional weekly Niño 3.4 reading — +3.1°C for the week centered September 23, 2026 — sorts into bands the same way: neutral below +0.5°C, weak +0.5–0.9°C, moderate +1.0–1.4°C, strong +1.5–1.9°C, and very strong at +2.0°C or above — the tier reached only by 1982-83, 1997-98 and 2015-16 since 1950. The gap between the two readings is expected (RONI nets out the tropics' background warming), and the direction the event is moving — strengthening — matters as much as either number, since ENSO forecasts are ultimately a bet on trajectory, not a single snapshot. For the full mechanics of how these bands are defined, see the Niño 3.4 glossary entry.
Where is El Niño now?
The forecast odds above describe the ocean's trajectory; the live map shows its current location. Warm anomalies currently stretch as a ribbon along the equatorial Pacific, from the South American coast through the Niño 3.4 box that drives the headline number, toward the dateline. Panning the map week to week is the fastest way to see whether the event is still feeding — fresh warm water arriving from the west, ahead of the readings that will show up in next month's outlook.
See the live anomaly map →Is the event still being fed?
Warm water piles up below the thermocline before it ever reaches the surface, so the upper-300 m heat content leads Niño 3.4 by roughly one to three months. A reservoir that keeps filling under a flat surface means more warming is still to come; one that drains means the event is running out of fuel however warm the surface still looks.
| Month | Whole basin | Eastern half |
|---|---|---|
| Mar 2026 | 1.38 | 1.36 |
| Apr 2026 | 1.85 | 2.24 |
| May 2026 | 1.67 | 1.99 |
| Jun 2026 | 1.79 | 2.26 |
| Jul 2026 | 2.03 | 2.96 |
| Aug 2026 | 2.19 | 3.23 |
The eastern half is the half that surfaces first, and it currently reads 3.23 °C — up on the month, so the reservoir is still filling.
The single number above integrates the downwelling Kelvin wave driving the event. CPC also publishes the full depth–longitude structure as an animation — see the equatorial cross-section on CPC GODAS →
Source: NOAA CPC equatorial upper-300 m mean temperature anomaly (1981–2010 climatology), 1979–present. Updated monthly by CPC; anomalies are against the 1981–2010 climatology, which is a different baseline from the 1991–2020 one used for the weekly Niño 3.4 value — compare directions, not absolute figures across the two.
Monthly forecast updates
One analysis after each official monthly outlook: how the odds moved, what the models converged on, and what to watch next.
July 9, 2026
NOAA Raises the Odds of a Very Strong El Niño to 81%
The July outlook jumps very-strong odds from 63% to 81%, centers the peak on Oct–Dec 2026 — and the ocean is running ahead of 1997 and 2015.
June 12, 2026
NOAA Declares El Niño — and the Odds of a Very Strong Event Rise
The Advisory is official: ~100% odds El Niño lasts through winter, 88% at least strong, 63% very strong. How June 2026 compares to 1997 and 2015.
May 14, 2026
El Niño Has Arrived: The Pacific Crosses the Threshold
Weekly readings have crossed the +0.5°C line for the first time since the La Niña ended. Here's what must happen before an official declaration.