Last Updated on 3 weeks ago by TodayWhy Editorial
Three months ago, NOAA’s Climate Prediction Center gave a Super El Niño a 63% chance of forming this winter. In July, that number rose to 81%. By its August 13 update, the odds had climbed past 90% — with a 69% chance the event ranks as the strongest since 1950.
Why is a Super El Niño forming for winter 2026-27? Warm water that had been building beneath the surface of the tropical Pacific for months is now rising, and the atmosphere above it is responding in exactly the pattern that turns an ordinary El Niño into a historic one.
What a Super El Niño actually is
El Niño is one phase of a natural cycle called ENSO — El Niño Southern Oscillation — in which sea surface temperatures across the tropical Pacific swing between warmer-than-average (El Niño) and cooler-than-average (La Niña) states, with neutral conditions in between. The cycle doesn’t run on a fixed schedule; a full swing typically takes two to seven years, and each phase usually lasts nine to twelve months.
A “Super” El Niño isn’t a separate phenomenon, just an extreme version of the same one. According to Columbia Climate School, scientists classify ENSO strength by how far Pacific sea-surface temperatures deviate from long-term averages: weak is 0.5–0.9°C above normal, moderate 1.0–1.4°C, strong 1.5–2.0°C, and “very strong” — the Super El Niño category — anything exceeding 2.0°C. Since 1980, only three El Niño events have ever cleared that very strong threshold.
Note on terminology: While the phrase “Super El Niño” is widely used in media, it is not an official classification employed by NOAA, the World Meteorological Organization, or most national meteorological agencies. Scientists and operational forecasters prefer the term “very strong El Niño,” defined as a Niño-3.4 (or Relative Oceanic Niño Index) anomaly of +2.0 °C or greater. The informal “super” label can sometimes overstate the certainty or uniformity of impacts, which vary significantly by region.
Why this El Niño went from likely to “historic” so fast
Back in December 2025, the Pacific was still in a weak La Niña phase. It transitioned to neutral conditions, and by June 11, 2026, NOAA upgraded its official status from an “El Niño Watch” to an “El Niño Advisory” — meaning El Niño conditions were no longer just forecast, they were already being observed.
What pushed the forecasts steadily upward since then is a specific atmospheric feedback loop. Strong westerly wind bursts have been driving warm water across the Pacific, while rising motion and lower pressure have become established over the central and eastern basin. That combination is self-reinforcing: the stronger the ocean warming, the stronger the atmospheric response, which in turn pulls more warm water toward the surface. Meteorologists tracking the pattern describe current forecasts pushing “toward record strength,” with the strongest warm-water signals building earlier in the year than in most past events.
As of mid-August 2026, weekly sea-surface temperature anomalies in the Niño-3.4 region had already climbed into the upper range of previous very strong events (conventional index values near +2.7 °C in the week centered on 12 August). Subsurface temperature anomalies across the central and eastern equatorial Pacific remained strongly positive, providing the oceanic “fuel” for further intensification into the fall and winter.
Why forecasters keep revising the odds upward
The trajectory of NOAA’s own probability estimates tells the story better than any single snapshot: 63% in June, 81% in July, and above 90% by mid-August, with the strongest-since-1950 probability sitting at 69%. NOAA also puts the odds of El Niño persisting into early spring 2027 at 97%.
That kind of steady upward revision, rather than a single dramatic jump, reflects how ENSO forecasting actually works: each month brings fresh subsurface ocean temperature data, and this year, nearly every update has confirmed the warming was continuing rather than levelling off. As one CPC advisory scientist put it, subsurface temperatures across the central and eastern equatorial Pacific were already running significantly warmer than average months ago, with that excess heat steadily rising toward the surface — the key precondition for El Niño to strengthen further.
Why this Super El Niño matters beyond a warmer ocean
A Super El Niño doesn’t stay contained to the Pacific. It reshapes the jet stream and pressure patterns across the globe, and forecasters are already tracing its influence into the coming Northern Hemisphere winter. NOAA’s seasonal outlook points toward above-average temperatures across much of the US, with wetter conditions favoured across the South and portions of the Southwest.
The Atlantic hurricane season feels El Niño’s effects too, though not in the direction people often assume. Stronger El Niño events tend to increase sinking air and wind shear across the Atlantic basin, conditions that are hostile to tropical storm formation and can tear apart systems that do form. That’s a genuine climatological signal, distinct from any single storm’s fate in a given season.
Beyond North America and the Atlantic, a very strong El Niño typically reshapes rainfall patterns across the tropics and subtropics. Historical analogues (1982–83, 1997–98, 2015–16) produced severe drought and elevated wildfire risk across Indonesia, Australia and parts of Southeast Asia, while bringing heavy rainfall and flooding risk to the western coasts of South America (especially Peru and Ecuador) and parts of East Africa. These teleconnections are probabilistic rather than deterministic; local outcomes also depend on other climate drivers such as the Indian Ocean Dipole and the Madden–Julian Oscillation.
Important caveats remain. Although the probability of a very strong event exceeds 90 %, model ensembles still show a spread in peak intensity. Whether the October–December 2026 Relative Oceanic Niño Index ultimately surpasses every previous event since 1950 (the 69 % “historic” threshold) depends on the precise metric used and on how the atmosphere–ocean coupling evolves in the coming months. Strong El Niño events also tend to decay rapidly after their peak, which is why the chance of persistence into spring 2027, while high, is not 100 %.
Why 1982-83, 1997-98 and 2015-16 are the comparisons everyone reaches for
Those are the only three “very strong” El Niño events on record since 1980, which is why forecasters keep measuring the current one against them. The 1982-83 event was, by most accounts, the most devastating: trade winds collapsed and reversed, triggering droughts, dust storms and wildfires across Australia, Africa and Indonesia while Peru and parts of South America saw some of the heaviest rainfall ever recorded. It was later linked to nearly 2,000 deaths and more than $13 billion in damages.
The winter of 1997-98 brought the second warmest and seventh wettest winter in the US since 1895, with the national average running roughly 2.8°C above normal. Then came 2015-16, when the tropical Pacific averaged 2.4°C above normal, the Northern Pacific saw a record 16 tropical cyclones, and a 500-year drought forced water rationing in Puerto Rico. 2015 became the warmest year on record at the time — a title it held only until 2023.
Current model forecasts for 2026-27 cluster in that same very-strong range, with some runs suggesting the anomaly could edge past those historic peaks and others landing just under them. Whether it ultimately claims the number-one spot is still genuinely uncertain, since different models measure and average sea-surface anomalies in slightly different ways — but every major forecasting centre agrees the event is tracking toward the upper end of the historical record.
Why a stronger climate doesn’t necessarily mean a stronger El Niño
It would be easy to assume that a warming planet is automatically supercharging this cycle, but the scientists who study ENSO are more cautious than that. “Even though we have a huge increase of global mean surface temperature, El Niños are not becoming stronger,” Columbia climate professor Mingfang Ting has said — a reminder that rising background temperatures and El Niño intensity are not the same trend, however tempting it is to link them.
There’s also a counterintuitive upside to a very strong event, according to Columbia meteorologist Andrew Kruczkiewicz: the stronger an El Niño or La Niña becomes, the more predictable the climate system tends to be, which in turn gives forecasters more confidence and gives emergency managers, energy companies and public health officials more lead time to prepare. Compared with the record-breaking 1997-98 event, he notes, monitoring tools, data and forecasting have all improved substantially in the decades since.
Frequently asked questions
What makes an El Niño a “Super” El Niño?
It’s a matter of intensity rather than a different phenomenon: scientists classify an El Niño as “Super” when sea surface temperature anomalies in the key tropical Pacific monitoring region substantially exceed the threshold for an ordinary event, historically only reached a handful of times.
How likely is a Super El Niño this winter?
As of NOAA’s August 13, 2026 outlook, there was a greater than 90% chance of a very strong El Niño during fall and winter 2026-27, up from 63% in June and 81% in July, with a 69% chance it ranks as the strongest event since 1950.
How does El Niño affect hurricane season?
Stronger El Niño events tend to increase wind shear and sinking air across the Atlantic basin, conditions that generally suppress tropical storm formation and intensification, even though any individual storm’s path or strength depends on many other factors too.
Was there really a La Niña just months before this El Niño formed?
Yes. The tropical Pacific was in a weak La Niña phase from roughly December 2025 through February 2026, before transitioning to neutral conditions and then rapidly building toward El Niño by summer.
How does this event compare to past Super El Niños?
Using the conventional threshold of +2.0 °C or greater in the Niño-3.4 region, only three El Niño events since 1980 are universally classified as very strong: 1982–83, 1997–98 and 2015–16. (Some earlier events, notably 1972–73, also reached or exceeded this level depending on the index and baseline period employed. Classifications can differ slightly between the traditional Oceanic Niño Index and NOAA’s newer Relative Oceanic Niño Index.
Is climate change making this Super El Niño stronger?
Not clearly, according to the scientists who study it. Despite significant increases in global average temperature in recent decades, researchers say El Niño events themselves are not becoming more intense as a direct result — the two trends are related to the climate system but are not the same thing.
How long is this El Niño expected to last?
NOAA estimates a 97% chance El Niño conditions persist into early spring 2027, with peak intensity most likely arriving in late fall or early winter 2026.
This article summarizes the official NOAA Climate Prediction Center outlook issued on 13 August 2026 together with supporting information from the International Research Institute for Climate and Society and Columbia Climate School. It is intended as a plain-language overview rather than a technical forecast. Readers seeking the most detailed guidance should consult the primary ENSO Diagnostic Discussion and the latest probabilistic strength outlooks directly from NOAA CPC.