Forecasters warn of a 62% chance of El Niño emerging by summer 2026, with AccuWeather estimating 15% odds of a super event by November that could drive global heat records higher amid ongoing climate trends.
The tropical Pacific is undergoing a rapid shift. A weak La Niña, the cool phase of the El Niño-Southern Oscillation (ENSO), has dominated recent months, cooling sea surface temperatures by at least 0.5°C below average. However, the National Oceanic and Atmospheric Administration’s (NOAA) Climate Prediction Centre announced this week that La Niña will end within weeks as subsurface ocean heat builds and trade winds weaken.
ENSO-neutral conditions are favoured through May-July 2026 with a 55 per cent probability. By June-August, the odds flip dramatically: a 62 per cent chance of El Niño development, according to NOAA’s latest diagnostic discussion issued on 12 March 2026. El Niño occurs when warmer waters pool in the eastern equatorial Pacific, disrupting atmospheric circulation and the jet stream. This natural cycle typically recurs every 2-7 years and lasts 9-12 months once established.
The current warming signals – rising sea temperatures and reduced easterly winds – are consistent with historical transitions. Forecasters note that while the exact timing has shifted slightly later than earlier models suggested, the trajectory toward El Niño is strengthening.
Rising Odds of a Supercharged Event
Not all El Niño episodes are equal. A standard event requires sea surface temperatures in the Niño-3.4 region to exceed 0.5°C above average for three consecutive months. A “super El Niño,” however, pushes anomalies to 2°C or more, amplifying global effects.
AccuWeather’s long-range team, led by meteorologist Paul Pastelok, estimates a 15 per cent probability of such an extreme event forming by the end of the Atlantic hurricane season in November. “Intensity is uncertain but there is potential for a moderate to possibly strong El Niño this fall into winter,” Pastelok told reporters. Water temperatures in the equatorial Pacific and Indian Ocean already support this outlook.
NOAA’s Climate Prediction Centre places the chance of a strong El Niño, at roughly one-in-three between October and December 2026. While forecasters stress that peak strength remains “very uncertain,” subsurface heat content in the Pacific is already elevated, matching patterns seen before powerful events.
LiveScience and AccuWeather reports, summarised in recent coverage, highlight that if the system intensifies to super status, it would rank among the strongest on record, similar to the 1997-98 and 2015-16 episodes that shattered temperature benchmarks.
Super El Niño and Its Mechanics
During a super El Niño, vast pools of warm water shift eastward, suppressing upwelling of cooler deep water off South America. This alters the Walker Circulation, weakening easterly trade winds and triggering a feedback loop that sustains the warming.
The atmospheric response cascades worldwide. The jet stream shifts southward, steering storm tracks and precipitation patterns away from their usual positions. In the United States, northern states often experience warmer, drier winters, while the Gulf Coast and Southeast face heightened flooding risks. Tropical cyclone activity in the Atlantic typically decreases as vertical wind shear increases.
Beyond weather, the excess ocean heat releases massive energy into the atmosphere. Combined with background global warming from greenhouse gases, even moderate El Niño years frequently set new global temperature records. A super event magnifies this effect dramatically.
Global Temperature and Climate Implications
The central concern is unprecedented heat. NOAA and independent analysts warn that a strong or super El Niño could push average global surface temperatures to new extremes in 2026 and especially 2027. The hottest years on record – 2023 and 2024 – occurred during or immediately after El Niño influence, with the pattern adding roughly 0.1-0.2°C to annual averages.
Climate scientist Zeke Hausfather of Berkeley Earth noted in recent commentary that a strong El Niño would “boost temperatures in 2026 a bit, but it will have a particularly large effect on temperatures in 2027 and put that year on track to probably be the warmest year on record after 2024.”
Beyond records, impacts could include intensified heatwaves, coral bleaching, and disruptions to agriculture and water supplies across multiple continents. In regions like India, where monsoon rains support hundreds of millions, a developing El Niño often correlates with weaker rainfall, though exact outcomes depend on the event’s strength and timing.
Hurricane seasons in the Atlantic may see reduced activity, while the eastern Pacific could experience heightened tropical storm risk. Ecosystems from the Galápagos to Australia’s Great Barrier Reef face stress from warmer waters.
Forecasters emphasise monitoring. NOAA has issued an El Niño Watch, and models will be updated monthly. While probabilities remain moderate for a super event, the baseline 62 per cent chance of any El Niño developing this summer already signals a shift from recent La Niña cooling.
