This year's El Niño will almost certainly become the strongest ever recorded, an analysis by a prominent climate researcher has warned. Though other scientists have cautioned that it's still too early to say what it will unleash.

Dynamical models now assign a 90% chance of the 2026-2027 El Niño being an all-time record event, sending temperatures in the Pacific Ocean up to around 3.6 degrees Celsius (6.5 degrees Fahrenheit) above average, according to an analysis by Zeke Hausfather, a research scientist at Berkeley Earth and an author of the Intergovernmental Panel on Climate Change's Seventh Assessment Report.

As the warm phase of a multiyear natural climate pattern, the El Niño could bring unprecedented temperature extremes to an already-warming world. The natural climate pattern is infamous for boosting global temperatures and fueling disruptive weather events such as floods and droughts.

A strong El Niño doesn't guarantee more severe weather impacts. The current El Niño models are also imperfect predictions of what's to come, and we won't know the true nature of this El Niño event until it peaks, likely later this year. However, forecasters have been warning of potentially supercharged El Niño conditions for months, and as more data emerges, there are more reasons to prepare.

According to projections by the World Meteorological Organization, the current El Niño — officially declared on June 11 — is on track to rapidly develop into a "strong" event between July and September. The National Oceanic and Atmospheric Administration's (NOAA) Climate Prediction Center now predicts a more than 80% likelihood of very strong El Niño conditions taking hold by the end of the year, ranking this El Niño event among the largest in the historical record.

"These are striking forecasts," Emily Black, a professor of terrestrial processes and climate at the University of Reading and a senior scientist at the National Centre for Atmospheric Science in the U.K., told Live Science in an email. "El Niño forecasts always come with uncertainty, but the level of agreement between models at this time of year, combined with the observed warming already underway in the tropical Pacific, means this should be taken very seriously."

"The important point is that a very strong El Niño would substantially shift the odds of damaging weather in many parts of the world, particularly in the Global South — with severe impact on livelihoods," Black added.

The International Rescue Committee, a humanitarian organization, has warned that the intense El Niño conditions threaten to unleash severe flooding and drought across East Africa and Asia, hitting some of the most vulnerable communities, Al Jazeera reported Tuesday (July 14).

During El Niño, warmer waters gather east of the equatorial Pacific, forcing the jet stream south. In the U.S., this typically brings warmer, drier conditions to the Northeast, while the Gulf Coast and Southeast experience an increased risk of flooding. Globally, the net result of the warmer waters is more heat in the atmosphere, on top of the temperature rise from human-driven global warming.

"El Niño is a natural climate phenomenon, but it is now happening against the backdrop of a much warmer planet," Black said. "That matters because a strong El Niño releases heat and energy into an already warmed world."

"This does not mean every impact can be attributed simply to El Niño or simply to climate change," Black added. "The two interact. El Niño can load the dice towards drought in some regions, flooding in others, marine heatwaves, disrupted monsoons and unusually high global temperatures. Climate change makes many heat extremes more severe and can intensify heavy rainfall because a warmer atmosphere can hold more moisture."

The last El Niño event occurred between 2023 and 2024. Both years broke temperature records, with 2024 becoming the hottest on record and the first to breach the 1.5-degree- Celsius (2.7 degrees Fahrenheit) warming limit set by the 2016 Paris Agreement. The current El Niño is forecast to be more intense than the one in 2023 and 2024, with the projected "very strong" status putting it in a different class of severity.

The strongest El Niño in history?

Hausfather's analysis reports that there's around a 90% chance that the current El Niño will be the strongest ever recorded, with data from multimodel forecasts suggesting that it may obliterate the previous record.

"With the July runs now in from 667 ensemble members across 14 different seasonal forecast models, it looks like this year's El Niño is not only very likely to be the strongest event since reliable records began ‪—‬ it may end up the strongest by a truly mind-blowing margin," Hausfather wrote in The Climate Brink Substack post published Monday (July 13).

NOAA recognizes El Niño conditions when the eastern tropical Pacific Ocean is at least 0.5 C (0.9 F) warmer than the historical average, while wind, surface pressure and rainfall in the region are also consistent with El Niño conditions. The El Niño is then categorized as weak, moderate, strong or very strong. A very strong El Niño (above 2 C, or 3.6 F, warmer than the historical average) is often nicknamed a "super" El Niño, though it's not a scientific term.

The July models suggest that temperatures will likely sail past 2 C above average in the coming months and could potentially even exceed 3.5 C (6.3 F) above average by the end of the year. This is based on newly introduced sea surface temperature forecasts that account for rising background temperatures that can inflate El Niño warming figures. In the traditional and most widely used indices, the temperature-anomaly forecasts cluster closer to 4 C (7.2 F), with some even exceeding 4 C.

In The Climate Brink Substack, Hausfather noted that the multimodel median for the event's peak is currently forecast at 3.6 C (6.5 F), or around 0.8 C (1.4 F) hotter than the prior record holder (2.75 C, set in the 2015-2016 El Niño event). Hausfather wrote that around 91% of ensemble members (individual computer models) have this El Niño exceeding the 2015-2016 record at their peak — around 77% likelihood in the newly introduced indices.

However, Black stressed that the models are still estimates, and not guarantees.

"It is certainly plausible that this could become a record-breaking El Niño, and the latest forecasts make that a real possibility rather than a remote one," Black said. "However, I would still be cautious about treating any probability estimate as a certainty."

"There are two reasons for caution," she added. "First, this event has not peaked yet, and El Niño events usually reach their maximum strength later in the year. Second, 'strongest ever recorded' depends on the index, dataset and baseline used."

"Impacts are what matter"

The most severe El Niño events have left a trail of devastation in their wake. For example, the 2015-2016 El Niño saw a record-breaking hurricane season in the central North Pacific, severe drought in the Caribbean and Ethiopia, and, of course, abnormally hot global temperatures, according to NOAA's Climate.gov. If the forecasts pan out, the current El Niño will match or exceed the 2015-2016 event, as well as an even more infamous super El Niño that occurred between 1877 and 1878, long before modern recordkeeping of El Niño began in 1950.

The 1877-1878 event likely fueled an extreme drought that fed into the 1876-1878 global famine, which ultimately killed more than 50 million people — making it among the worst humanitarian crises in history. However, the disaster was far from just an environmental one, with extractive colonial agricultural policies helping to create conditions for a massive humanitarian crisis. Nonetheless, the famine highlights what can happen when environmental and socioeconomic factors converge.

Even though the world has changed a lot since the 19th century, experts have said a super El Niño could still cause severe shocks to our food systems. This is especially true at a time when researchers say food insecurity is not just confined to low-income countries and that climate change is already pushing agricultural systems to the brink.

The El Niño-Southern Oscillation cycle triggers a warm El Niño and then a cold La Niña roughly every two to seven years, with each phase typically lasting around nine to 12 months. Carbon Brief has predicted that 2026 is likely to be the second-warmest year on record, with the intensifying El Niño increasing the likelihood that 2027 will be the warmest year ever recorded.

The strength of an El Niño event does not necessarily correspond to the size of its influence or impact, according to the Climate Prediction Center. More severe events typically, but not always, increase the certainty of expected impacts. Black believes the impact of an El Niño event is more important than where it ranks in the observational record.

"Records are compelling, but impacts are what matter," Black said. "Even if it falls just short of a record, a very strong El Niño can still have serious consequences. Finally, these forecasts are concerning, but they are also useful: they give societies time to anticipate possible impacts and act before the worst effects are felt."