The 2026 El Niño Is Now Very Strong—But a Record Is Not Yet Confirmed

El Niño is strengthening at an exceptional pace in the tropical Pacific. Its latest weekly Relative Oceanic Niño Index (RONI) reached +2.0°C—the threshold for NOAA’s highest, “very strong” category—but that alone does not establish a new historical record. NOAA compares events using a three-month running RONI, and the key October–December period is still ahead.125

Why this event is notable—but not yet a confirmed record

NOAA issued an El Niño Advisory on June 11. By September, the agency said the event had a greater than 90% chance of becoming very strong during Northern Hemisphere fall and winter 2026–27.119

The more consequential forecast is NOAA’s 75% chance that the October–December three-month RONI will reach or exceed +2.5°C. That is the threshold NOAA identifies as stronger than previous El Niño events in its record back to 1950.2

In other words, the event is already very strong on a short-term reading, and a historic seasonal peak is more likely than not. It remains a forecast, however, rather than an achieved record.

What RONI measures

RONI is designed to distinguish the El Niño signal from broad tropical-ocean warming. It starts with the sea-surface-temperature anomaly in the Niño-3.4 region of the equatorial Pacific and subtracts the tropical-mean sea-surface-temperature anomaly; NOAA also adjusts its variance to align with the original Niño-3.4 index.1

That matters in an unusually warm climate. A high RONI indicates that the central Pacific is anomalously warm relative to the wider tropics, rather than simply reflecting a warm global ocean background.

How long could it last?

The World Meteorological Organization expects the event to strengthen further and peak toward the end of 2026. Its forecasts put the likelihood of El Niño persisting through February 2027 at close to 100%.35

Persistence does not mean every impact will last equally long or occur everywhere. ENSO changes the odds of weather patterns; it does not determine the outcome of each storm, season, or locality.

Atlantic hurricanes are already showing the expected signal

NOAA’s updated 2026 Atlantic hurricane outlook identifies a below-normal season as the most likely result. The agency cites a strengthening El Niño through the peak Atlantic hurricane months as part of its reasoning.18

El Niño often makes the Atlantic less favorable for tropical cyclones by increasing disruptive upper-level wind shear. Reporting around the climatological peak of the season noted that no Atlantic hurricanes had yet formed.20

The Pacific response is different. WMO notes that El Niño can support hurricane activity in the central and eastern Pacific while hindering it in the Atlantic.27 That can heighten the need for monitoring in places such as Hawaii, but it does not amount to a forecast of a Hawaiian landfall.

What it may mean for Indonesia, Hawaii and markets

El Niño is commonly associated with drier conditions across parts of Indonesia, which can elevate drought, fire-weather and haze concerns. The supplied evidence does not support attributing a specific 2026 Indonesian wildfire outcome to this event yet, so that risk should be treated as a preparedness concern rather than a confirmed impact.

For Hawaii, the defensible takeaway is similar: monitor drought and central-Pacific tropical-cyclone conditions rather than infer a certain local outcome.

There is also insufficient reliable evidence in the supplied reporting to identify a verified, event-driven move in weather-derivative markets.

North American winter: stronger signals in broad patterns than in local snowfall

A strong El Niño often favors a more active southern U.S. storm track, increasing the odds of wetter conditions in parts of the southern and southeastern United States.56 NOAA-linked seasonal reporting also shows the strongest odds of above-average temperatures across the northern tier of the United States.47

For Canada and the northern U.S., that pattern can favor a relatively mild winter. For the southern U.S., a wetter pattern can raise flooding exposure where major storms arrive. Neither is a location-by-location guarantee.

What about Utah?

Utah sits near the edge of broad El Niño composites, so outcomes depend heavily on storm track, elevation and temperature. A wetter cool season—especially farther south—can improve the odds of precipitation, but it does not guarantee deep snow at every elevation. Lower-elevation precipitation may fall as rain, while mountain snowpack depends on whether individual storms arrive cold enough.

The West Coast Kelvin wave is the nearer-term coastal concern

El Niño-related changes in equatorial winds can generate Kelvin waves that cross the Pacific. After reaching the Americas, they can turn northward as coastally trapped waves along North America’s Pacific coast.48

A new wave was expected to add roughly 6 inches to sea level off California and potentially persist for months, according to reporting citing coastal-wave expert Dillon Amaya.45 Other reporting projected total water levels along California’s coast, including the wave, could reach about 10 to 14 inches above normal by mid-October.52

The practical consequence is not a permanent jump in sea level. It is a temporary regional anomaly that can compound high tides, surf and storms—raising the risk of beach erosion, nuisance flooding and more damaging coastal inundation. Effects farther north, including British Columbia, depend on the wave’s evolution and local tides and weather.

Global heat risks extend into 2027

WMO expects unusually warm conditions across much of the world in coming months as this El Niño intensifies, with climate impacts continuing into 2027.35 El Niño can help transfer ocean heat into the atmosphere, so global temperature effects often lag the growth of the Pacific ocean signal.

The event therefore raises the risk of extraordinary global warmth alongside altered drought, heavy-rain and coastal-extreme patterns. But the scale of any global-temperature record, the precise regional distribution of impacts and any global mean sea-level increment cannot be reliably assigned from the available evidence alone.

Bottom line

The 2026 El Niño has developed from an official June onset into a very strong event by September. Its weekly +2.0°C RONI is striking, but the record question will be settled by the three-month average later this year. NOAA’s 75% odds of a historic October–December peak make that possibility substantial, while the most immediate actionable U.S. concern is heightened coastal flood exposure along California as a Kelvin wave overlaps with tides and storms.245