Scientists are still figuring out how strong the changes are. Some think it could be “one of the strongest El Niños in recent history.”
Can scientists still really trust El Niño forecasts?
Scientists have warned that while El Niño reduces the likelihood of hurricanes, storms can still form because the ocean stores excess heat.
Weeks after the Pacific engine that drives the world’s weather shifted into neutrality, meteorologists and scientists are now focusing on El Niño, a signal that a warm period is underway.
What’s gaining attention is that global predictive models are showing early signs.
Virtually all models indicate that El Niño will occur within the next few weeks, and the median estimate across those models is “a pretty strong phenomenon,” said Zeke Hausfather, director of climate and energy at the Breakthrough Institute and a researcher at Berkeley Earth. “This would put us on track for the strongest El Niño event in recent history, but it’s too early to know for sure.”
The prospect of a strong El Niño event has raised concerns that further heat waves, including ocean heat waves, will be added to longer-term climate warming, given that it is expected to arrive at a time when much of the West and parts of the Pacific have already experienced several months of warmer-than-normal temperatures. The forecast has triggered global alarm as this pattern has a major impact on global weather, with strong events potentially having ripple effects for months to come.
El Niño has fueled wildfires, caused extreme flooding and severe droughts. These caused widespread coral bleaching and disrupted the migration and feeding of marine life.
However, uncertainties still remain. Spring is known to be a difficult time for El Niño models.
In its latest information for April, the National Oceanic and Atmospheric Administration puts the probability of a strong El Niño at 1 in 4. Since then, sea surface temperatures have been rising in the El Niño region. NOAA’s next update will be on May 14th.
What is El Niño?
El Niño Southern Oscillation is “probably the most influential climate driver on Earth,” according to the Cooperative Research Institute for Environmental Sciences at the University of Colorado Boulder.
The natural repeating pattern in the central and eastern Pacific Ocean cycles through three phases: El Niño, La Niña, and neutral. First recorded by fishermen off the west coast of South America in the 1600s, its effects extend far beyond the coast as it brought unusually warm seawater into the eastern Pacific Ocean around Christmas.
The Pacific Ocean is so large that disruptions there can have far-reaching effects. It affects where the world’s ocean heat is released into the atmosphere, atmospheric circulation, temperature, and precipitation.
NOAA once said of the rest of the world’s atmosphere: “The arrival of El Niño in the Pacific is like a giant bell ringing so loudly it knocks dishes off the shelves of houses down the street.”
What is happening now?
The cold spell of La Niña disappears as the sun sets in early April, and El Niño is widely expected to begin in the coming weeks, although drought impacts may remain in some parts of the United States. Satellite data shows sea surface temperatures rose sharply in the central and eastern Pacific Ocean in April.
But higher-than-normal water temperatures aren’t enough to meet NOAA’s criteria for declaring an El Niño. It would require water nearly one degree warmer than the average for the El Niño region over a period of time, weakening the trade winds and weakening the atmospheric response accordingly.
The western and southwestern regions of the country experienced their warmest winter on record. According to NOAA, the Northeast Pacific Ocean reached a record high average temperature of about 69 degrees Celsius on September 9, 2025, and a marine heatwave continued throughout the winter and spring. NOAA’s latest sea surface temperature measurements show that in March, seawater in parts of the West Coast was about 3 to 4 degrees warmer than normal.
And on March 8, NOAA announced that the past 12 months in the northern 48 regions of the continent have been warmer than any other 12 months, with more than 40% of the continental United States experiencing severe to exceptional drought.
How strong is El Niño?
Forecasters and global models are seeing factors that suggest a strong El Niño is becoming more likely, including a growing plume of warm water in the Pacific Ocean, but the potential strength of the event remains to be seen.
Like Housefather, Brian McNoldy, a senior research fellow at the University of Miami, is among those who maintain a website that regularly updates global predictive models. McNoldy also issued a warning in a recent social post.
“There’s been a lot of talk about the expected development of a strong #ElNino,” McNoldy said. The models are “in very good agreement in that respect. However, the consensus is that it is an ‘average’ strong El Niño, not a historical one.”
NOAA said in April that the final outcome would depend on wind patterns along the equatorial Pacific Ocean during the summer.
Several factors come into play. First, according to the Columbia Climate School at Columbia University, computer modeling skills improve from June to December compared to the beginning of the year. Therefore, the predictions are likely to become more accurate as the summer progresses.
Other surrounding weather patterns moving through the atmosphere can also influence the formation and strength of El Niño. And this year, NOAA began using an adjustment index that takes into account warming from climate change before calculating intensity, Hausfather said. Although this method is controversial, it is certainly a better way to remove the effects of “human-induced global warming” so that El Niño does not appear to be getting stronger over time, he said.
Do all El Niño events produce the same phenomenon?
The three most severe El Niños are considered to be in 1982-1983, 1986-1987, and 2015-2016. They are blamed for climate disasters around the world, including floods in Africa, extreme droughts and famines, a rise in mosquito-borne virus cases on the East Coast, and the death of nearly a million seabirds in a large “clump” of ocean water in the Pacific Ocean.
Do past El Niño events demonstrate that it will occur later this year? Not necessarily. Years ago, NOAA scientist Dike Arndt humorously explained this in a 2015 blog post on NOAA’s former website, Climate.gov.
At your favorite establishment, the staff may bring you a specialty drink when you enter. But one night, you might walk in and the bartender might hand you something completely unexpected, writes Arndt, now director of the agency’s National Center for Environmental Information.
“El Niño is like that bartender,” he wrote. Meeting the bartender may increase your chances of getting your favorite drink, but it’s not guaranteed. “In other words, due to El Niño, the bartender may not bring you what you order.”
hurricane and el nino
One notable effect of El Niño is that tropical activity in the Atlantic Ocean tends to decrease. Changes in the path of the jet stream over the United States can cause downdrafts and sinking winds, which are known to reduce but not eliminate hurricane activity in key areas of the Atlantic Ocean where hurricanes occur frequently. These winds can prevent a storm from building the self-supporting structures needed to become a hurricane.
But the National Hurricane Center and others warn that storms, even large and devastating hurricanes, can and do occur in El Niño years, especially in the Gulf of America (formerly the Gulf of Mexico). Comparing 15 of the warmest El Niños on record, at least 37 named storms have made landfall in the continental United States, including 14 hurricanes.
La Niña and wildfires
Researchers warn that even if conditions change, the effects of La Niña could still contribute to an increase in wildfires.
A study by Cooperative Research Institute and NOAA researchers found a strong link between fall La Niña events and increased spring fire activity. It reported a two-fold increase in the relative risk of major burns in the South, Southwest, and Rocky Mountains during the summer, and in the Great Basin and Northern California regions. Fall El Niño appears to increase the risk of large fires in the eastern and northern Rocky Mountains in the spring.
Andrew Hoell, a NOAA researcher and lead author of the study published in the Journal of Geophysical Research: Atmospheres, said the El Niño oscillation “represents a powerful tool for predicting the likelihood of large wildfires in some regions of the United States up to a year in advance.”
Once the engine of the vast Pacific Ocean gets going again, scientists will be looking at satellites and other instruments to determine how the world’s weather will change in the coming months.
See NOAA’s predicted sea surface temperature anomalies.
Click the buttons labeled “SST Anomalies” and “Outlook” at the top of the graph to see the forecast for the next 16 weeks.
Dinah Boyles Pulver, a national correspondent for USA TODAY, writes about violent weather, climate change and other news. Contact dpulver@usatoday.com or @dinahvp on Bluesky or dinahvp.77 on X or Signal.
