The World Meteorological Organization has issued a stark warning: the El Niño currently developing in the Pacific Ocean is "firmly established and strengthening rapidly," with a near-100 percent likelihood of persisting through February 2027 — and it could become one of the strongest such events since records began in 1950.

If the forecast holds, the world is about to experience a climate jolt that will shape weather patterns, food production, public health and economies across nearly every continent. Forecasters say the seasonal peak, expected around December 2026, could surpass the previous record set during the monster El Niño of 2015–16.

What exactly is happening in the Pacific, and why does it matter to people far from any ocean? Here is the full explainer.

Background: What Is El Niño?

El Niño is the warm phase of the El Niño–Southern Oscillation (ENSO), a naturally recurring climate pattern driven by changes in ocean temperatures and winds across the tropical Pacific. Under normal conditions, trade winds push warm surface water toward the west, allowing cooler, nutrient-rich water to well up along South America's coast. During El Niño, those trade winds weaken, and a vast pool of unusually warm water spreads across the central and eastern tropical Pacific.

That single change reorganizes weather worldwide. The ocean is Earth's largest store of heat and moisture, so when the Pacific releases extraordinary amounts of both into the atmosphere, rainfall patterns, storm tracks and temperature regimes shift across the globe — often in predictable ways.

Crucially, as WMO Secretary-General Celeste Saulo emphasizes, El Niño does not create new heat. It releases heat that the ocean has already stored. And that matters enormously right now, because the ocean is the warmest ever measured. El Niño is essentially a mechanism for the overheated ocean to exhale — pushing global temperatures upward on top of the long-term warming caused by greenhouse gases.

To understand the bigger picture of human-driven warming that El Niño amplifies, see our guides on what climate change is and its causes, effects and solutions.

What Happened: The WMO's Latest Update

The WMO's Global Seasonal Climate Update, reported in early October 2026 by outlets including BusinessLine, IFLScience and Reuters, delivers a series of striking numbers:

  • Sea-surface temperature anomalies in the Niño 3.4 region — the key monitoring zone — jumped from +1.6°C in June 2026 to +2.5°C in August 2026.
  • The forecast seasonal peak is around +3.7°C for the October–November–December period — the highest since observations began, beating the +2.6°C peak of November 2015 to January 2016.
  • There is a near-100% likelihood the event persists through February 2027.
  • The WMO describes it as "potentially one of the strongest since at least 1950."

A separate assessment by the Japan Meteorological Agency was even more dramatic: it said Pacific temperatures have reached up to 4.0°C above normal, making this the strongest El Niño ever recorded — surpassing the previous record of 3.6°C in December 1997.

The baseline context is alarming. August 2026 saw a mean global temperature of 16.96°C, tying July 2023 as the hottest month on record according to the Copernicus climate service. And a University of Chicago Climate Impact Lab projection, published last month, estimated that a "super El Niño" could cause up to 451,000 excess deaths globally between June 2026 and February 2027 — a figure that underlines the human stakes of what might sound like an abstract ocean measurement.

Adding fuel to the fire, a positive Indian Ocean Dipole is also peaking this month, with a +0.5°C anomaly for the October–December period — another warm-ocean pattern that compounds rainfall disruption across Asia, East Africa and Australia.

Why It Matters: A Map of Global Disruption

The WMO's update maps out where the strongest impacts are expected, and the list reads like a tour of the world's most vulnerable regions:

  • Drier than average: the Indian subcontinent, southern Central America, the Caribbean, and northwestern South America. For India, this raises the stakes of an already watched monsoon system.
  • Wetter than average: the Greater Horn of Africa, Central and East Asia, the northern Arabian Peninsula, parts of North America, and southeastern South America — bringing flood risk to regions that have suffered devastating floods before.
  • Record ocean temperatures across the central and eastern tropical Pacific by late 2026, threatening coral reefs, fisheries and marine ecosystems that hundreds of millions of people depend on.

El Niño events are also historically associated with: droughts that devastate harvests in Southeast Asia, southern Africa and Australia; wildfire seasons that spiral out of control (as seen during the 2015–16 event); surges in mosquito-borne disease as rainfall patterns shift; and disruptions to anchovy and other fisheries off South America.

The economic dimension is enormous. Agriculture, insurance, energy demand and commodity prices all respond to El Niño. A strong event can push global food prices upward, strain disaster-response budgets and complicate the energy transition as hydropower output fluctuates.

For individuals, the practical response starts at home: building resilience to heat, water disruption and extreme weather is no longer a theoretical exercise. Our guide on how to reduce your carbon footprint covers the longer-term actions that address the root causes El Niño is amplifying.

Key Facts

  • Event: El Niño in the tropical Pacific, described by WMO as "firmly established and strengthening rapidly"
  • Current anomaly: +2.5°C in the Niño 3.4 region (August 2026), up from +1.6°C in June
  • Forecast peak: ~+3.7°C for Oct–Nov–Dec 2026, expected December peak — highest on record, beating +2.6°C (2015–16)
  • Japan Meteorological Agency: Temperatures up to 4.0°C above normal — strongest ever recorded (previous 3.6°C, Dec 1997)
  • Likelihood of persistence through Feb 2027: Near 100%
  • WMO Secretary-General: Celeste Saulo; key message: El Niño releases stored ocean heat, it doesn't add heat — and the ocean is the warmest ever measured
  • Global temperature context: August 2026 averaged 16.96°C, tying the hottest month on record (Copernicus)
  • Health projection: University of Chicago Climate Impact Lab estimated up to 451,000 excess deaths globally June 2026–Feb 2027 from a "super El Niño"
  • Compounding factor: Positive Indian Ocean Dipole peaking in October (+0.5°C OND anomaly)
  • Source outlets: BusinessLine, IFLScience, Reuters, October 2026

What Happens Next

The peak is expected in December 2026. From there, the event should gradually decay through early 2027, though the WMO gives it a near-certain chance of lasting through February. The months between now and the peak are when the most intense weather anomalies will hit — and when early-warning systems, disaster preparedness and agricultural planning matter most.

One key question scientists will be watching: how does this event interact with long-term warming? Every strong El Niño of the past four decades has produced new global temperature records, and 2026 is starting from a higher baseline than any of them. If the +3.7°C peak materializes, 2026 or 2027 could set a new record for global heat.

Another question is what follows. El Niño events are frequently followed by La Niña — the cool phase — which brings its own set of disruptions. Forecasters will begin issuing those outlooks in early 2027.

For governments, the immediate imperative is preparation: securing food supplies, pre-positioning flood and drought relief, protecting public health systems ahead of disease shifts, and communicating risk clearly to farmers and coastal communities. The WMO's update is not a prediction of doom — it is a forecast with unusually high confidence, and high confidence is exactly what makes preparation possible.

The deeper story remains unchanged: El Niño is natural, but it is now playing out in a climate system humans have loaded with extra heat. The ocean is the warmest ever measured. What the Pacific exhales over the coming months will be felt on dinner tables, in hospital wards and in economies from Delhi to Lima.