I have been running elninoguide.com — a reference site for ENSO science and forecasts — and the data coming out of the tropical Pacific right now is worth paying attention to.
The numbers
As of mid-July 2026, the Oceanic Niño Index (ONI) — the 3-month running mean of SST anomalies in the Niño 3.4 region — sits at +1.2°C and climbing. That is already a moderate El Niño. The critical detail is the rate of change: the ONI was at -0.2°C in March. A 1.4°C swing in 12 weeks is one of the fastest ENSO transitions in the modern record.
The NOAA CFSv2 model ensemble projects a peak ONI of +2.0°C to +2.3°C for November-December 2026. The ECMWF SEAS5 agrees. The IRI/CPC plume forecast gives an 85% probability of El Niño persisting through March 2027.
For context: +2.0°C is the threshold for a "very strong" or "super" El Niño. The 1997-98 event hit +2.4°C. The 2015-16 event hit +2.6°C. The current forecast puts 2026-27 in that same tier.
Why this matters
A very strong El Niño is not just "the Pacific got warm." It is a global climate event with well-documented impact patterns:
- South America: Peru and Ecuador get catastrophic rainfall — 500-1,000mm where 50mm is a normal season. The 2015-16 event displaced over 100,000 people in northern Peru.
- California: 130-160% of normal precipitation. The 2015-16 El Niño ended California's historic drought. The flip side: Oroville Dam nearly failed in February 2017 when a heavy snowpack melted rapidly.
- Australia and Indonesia: 60-80% of normal rainfall. The 2015 Indonesian forest fires — amplified by El Niño drought — burned 2.6 million hectares and produced a haze crisis affecting 40 million people.
- India: Monsoon rainfall drops to 90-95% of normal. A "deficit" monsoon year reduces agricultural GDP by roughly 0.5 percentage points.
- Atlantic hurricanes: Suppressed. El Niño increases vertical wind shear over the tropical Atlantic, tearing apart developing cyclones. NOAA already cut the 2026 hurricane season forecast from 17-25 named storms to 12-17.
- Global economy: A 2023 Dartmouth study estimated the 1997-98 El Niño cost $5.7 trillion in global GDP over five years through persistent effects on growth rates, not just direct damage.
The real-time dashboard
I built an ENSO monitoring dashboard that pulls from NOAA and WMO public data to track ONI, sea surface temperature anomalies, subsurface heat content, and model forecasts — all updated automatically.
If you want to follow the data yourself rather than reading headlines:
What I am watching next
Three signals will determine whether this becomes a super El Niño:
- Westerly wind bursts (WWBs) in the western Pacific between August and October. These are episodes of sustained westerly winds near the Date Line that push warm water eastward. The number and strength of WWBs is the single best predictor of peak El Niño strength.
- Indian Ocean Dipole (IOD) interaction. A positive IOD often develops alongside strong El Niños and amplifies the drought signal for Australia.
- Subsurface heat content. The warm water volume in the upper 300 meters of the equatorial Pacific is already above normal — this is the fuel tank for continued warming.
I will update the site as new model runs come in.
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