• An 82% probability of El Niño persisting through August-October, rising to 84% for September-November .
• A 63% chance of a "very strong" El Niño during the November-January peak season, which NOAA meteorologist Michelle L’Heureux said “would rank among the largest El Niño events in the historical record” going back to 1950 .
• A separate forecast notes a 55% chance of a moderate-to-strong event and a 37% probability of a "strong" categorization specifically .

The CPC further reinforces this with an overall outlook of a 96% chance that El Niño will continue through the winter of 2026-27 .

World Meteorological Organization (WMO)

The WMO confirmed the onset of El Niño on June 2, 2026, with Secretary-General Celeste Saulo warning the phenomenon will fuel more extreme weather . The WMO’s model-based outlook is highly confident.

• An 80% probability that El Niño conditions would develop between June and August 2026, increasing to near or above 90% for the September-November period .
• The WMO’s Global Seasonal Climate Update for June-July-August projects the multi-model ensemble mean for the Niño-3.4 index will reach approximately +1.8°C, well above the El Niño threshold .
• Most models forecast the event will reach at least moderate strength, with a clear potential to intensify further .

The WMO emphasized this event is happening on top of already record-warm global temperatures, significantly raising the risk of heatwaves and other extreme events .

Australia’s Bureau of Meteorology (BoM)

The BoM officially declared that El Niño is “currently underway in the tropical Pacific” as of its mid-June update . The agency’s observations show the ocean and atmosphere are reinforcing each other, a key sign of a sustained event.

• Sea surface temperatures in the central tropical Pacific are above the BoM’s El Niño threshold of +0.8°C, with the latest weekly Niño-3.4 index at +0.92°C for the week ending June 14, 2026 .
• The BoM states the event is “likely to strengthen” and last until at least the end of the year, with all models, including its own, forecasting continued warming .
• A critical caveat from the BoM is that the strength of an El Niño does not “necessarily imply significant impacts on Australia's climate,” but the agency still warns that long-term climate change could amplify its effects, with below-average rainfall expected across much of southern and eastern Australia through spring .

The Multi-Model Consensus (IRI/Columbia)

The forecast from the International Research Institute for Climate and Society at Columbia University is the most statistically certain. The CCSR/IRI ENSO plume assigns a 98% probability to El Niño during May-July 2026, with that near-certain probability holding steady at 97-98% through the remainder of the year .

The State of the Pacific: Sea Surface Temperatures

The statistical models are backed by alarming physical observations. The warming is not uniform but is most pronounced in the eastern Pacific, a classic precursor to a powerful basin-wide event.

• The Niño-1+2 region in the far eastern Pacific is already at a startling +2.1°C above average, even as the more commonly cited Niño-3.4 index was at +0.7°C during a recent weekly measurement .
• The Niño-3.4 zone has since set a new daily temperature record for 16 consecutive days, reaching 29.32°C as of mid-June, a temperature approximately 1.6°C to 1.8°C above normal .
• These temperatures are developing on top of global oceans already at near-record warmth. April 2026 saw the second-highest sea surface temperatures ever recorded for the extra-polar oceans .

A Crucial Note on Record-Breaking Projections

While both the CPC and other outlets like CNN report that the 2026 event could become a "super El Niño" and rank "among the largest in the historical record," no official sourced evidence from the three major agencies supports a specific claim that sea surface temperature anomalies will surpass 3°C or definitively exceed the 1997 record . The multi-model ensemble mean from the WMO projects a peak of roughly 1.8°C, and even the highest-probability CPC forecast calls for anomalies averaging greater than 2°C for a "very strong" event . While a more severe outcome is possible, it is not the central projection from any of the three agencies.

Unverified Claims and Limitations

This report is strictly limited to the sourced and verified data from the designated monitoring agencies. Several claims included in initial questions for this research could not be independently verified and must be treated as unconfirmed until supported by direct sourcing:

• Warnings from the International Fund for Animal Welfare (IFAW)
• The figure of 150+ million hectares burned globally in early 2026
• The controversy over the dismantling of the Ocean Observatories Initiative’s deep-sea sensors

In the interests of accuracy, these elements have been excluded from this synthesis.

• An 82% probability of El Niño persisting through August-October, rising to 84% for September-November .
• A 63% chance of a "very strong" El Niño during the November-January peak season, which NOAA meteorologist Michelle L’Heureux said “would rank among the largest El Niño events in the historical record” going back to 1950 .
• A separate forecast notes a 55% chance of a moderate-to-strong event and a 37% probability of a "strong" categorization specifically .

The CPC further reinforces this with an overall outlook of a 96% chance that El Niño will continue through the winter of 2026-27 .

World Meteorological Organization (WMO)

The WMO confirmed the onset of El Niño on June 2, 2026, with Secretary-General Celeste Saulo warning the phenomenon will fuel more extreme weather . The WMO’s model-based outlook is highly confident.

• An 80% probability that El Niño conditions would develop between June and August 2026, increasing to near or above 90% for the September-November period .
• The WMO’s Global Seasonal Climate Update for June-July-August projects the multi-model ensemble mean for the Niño-3.4 index will reach approximately +1.8°C, well above the El Niño threshold .
• Most models forecast the event will reach at least moderate strength, with a clear potential to intensify further .

The WMO emphasized this event is happening on top of already record-warm global temperatures, significantly raising the risk of heatwaves and other extreme events .

Australia’s Bureau of Meteorology (BoM)

The BoM officially declared that El Niño is “currently underway in the tropical Pacific” as of its mid-June update . The agency’s observations show the ocean and atmosphere are reinforcing each other, a key sign of a sustained event.

• Sea surface temperatures in the central tropical Pacific are above the BoM’s El Niño threshold of +0.8°C, with the latest weekly Niño-3.4 index at +0.92°C for the week ending June 14, 2026 .
• The BoM states the event is “likely to strengthen” and last until at least the end of the year, with all models, including its own, forecasting continued warming .
• A critical caveat from the BoM is that the strength of an El Niño does not “necessarily imply significant impacts on Australia's climate,” but the agency still warns that long-term climate change could amplify its effects, with below-average rainfall expected across much of southern and eastern Australia through spring .

The Multi-Model Consensus (IRI/Columbia)

The forecast from the International Research Institute for Climate and Society at Columbia University is the most statistically certain. The CCSR/IRI ENSO plume assigns a 98% probability to El Niño during May-July 2026, with that near-certain probability holding steady at 97-98% through the remainder of the year .

The State of the Pacific: Sea Surface Temperatures

The statistical models are backed by alarming physical observations. The warming is not uniform but is most pronounced in the eastern Pacific, a classic precursor to a powerful basin-wide event.

• The Niño-1+2 region in the far eastern Pacific is already at a startling +2.1°C above average, even as the more commonly cited Niño-3.4 index was at +0.7°C during a recent weekly measurement .
• The Niño-3.4 zone has since set a new daily temperature record for 16 consecutive days, reaching 29.32°C as of mid-June, a temperature approximately 1.6°C to 1.8°C above normal .
• These temperatures are developing on top of global oceans already at near-record warmth. April 2026 saw the second-highest sea surface temperatures ever recorded for the extra-polar oceans .

A Crucial Note on Record-Breaking Projections

While both the CPC and other outlets like CNN report that the 2026 event could become a "super El Niño" and rank "among the largest in the historical record," no official sourced evidence from the three major agencies supports a specific claim that sea surface temperature anomalies will surpass 3°C or definitively exceed the 1997 record . The multi-model ensemble mean from the WMO projects a peak of roughly 1.8°C, and even the highest-probability CPC forecast calls for anomalies averaging greater than 2°C for a "very strong" event . While a more severe outcome is possible, it is not the central projection from any of the three agencies.

Unverified Claims and Limitations

This report is strictly limited to the sourced and verified data from the designated monitoring agencies. Several claims included in initial questions for this research could not be independently verified and must be treated as unconfirmed until supported by direct sourcing:

• Warnings from the International Fund for Animal Welfare (IFAW)
• The figure of 150+ million hectares burned globally in early 2026
• The controversy over the dismantling of the Ocean Observatories Initiative’s deep-sea sensors

In the interests of accuracy, these elements have been excluded from this synthesis.