El Niño 2026 vs 2023-24: Comparing Two Strong ENSO Events Just Two Years Apart
Published: July 25, 2026 · 7 min read
TL;DR
The 2026 El Niño is developing faster and with more subsurface heat than 2023-24 at the same point in the calendar. But the rapid return to El Niño — just two years after the last one peaked — means the world faces another strong event before some regions have fully recovered from the last one. If the 2026 event reaches Super El Niño status, it would mark the closest pair of strong El Niños since 1963-65.
Head-to-Head: July Comparison
| Metric (July comparison) | 2026 | 2023 |
|---|---|---|
| Niño-3.4 anomaly | +1.4°C | +1.1°C |
| Niño-3 anomaly | +1.7°C | +1.3°C |
| Subsurface heat (0-300m) | +1.8°C | +1.3°C |
| Ocean Heat Content index | +2.1 | +1.6 |
| SOI (30-day) | -12.3 | -9.1 |
| Westerly Wind Bursts (since March) | 5 | 3 |
| Model peak forecast (OND) | +1.9°C (avg) | +1.6°C (avg) |
| Model spread | +1.4 to +2.8°C | +0.8 to +2.5°C |
| Prior ENSO state | La Niña (1 year gap) | La Niña (3 years) |
| Global avg temp (year to date) | +1.52°C | +1.36°C |
By every ocean metric, the 2026 event is ahead of where 2023 was at the same calendar date. Higher Niño indices, more subsurface heat, stronger atmospheric coupling, and a warmer background state. The model forecasts are also more aggressive — the average projected peak for 2026 (+1.9°C) is higher than what models were forecasting for 2023 at this point (+1.6°C).
The Different Launchpads
The two events launched from different starting conditions, and that matters. The 2023-24 El Niño emerged after a rare triple-dip La Niña (2020-2023) — three consecutive La Niña winters. The subsurface ocean had been cold for three years. When the switch finally flipped, there was significant pent-up heat to release, but the transition took longer because the cold pool was deep.
The 2026 event, by contrast, is launching barely 14 months after the 2023-24 El Niño faded and only about 12 months after the brief La Niña of 2025 ended. The subsurface didn't have time to fully cool. Some researchers think this is why the 2026 event is intensifying faster — the ocean was primed. The rapid turnaround also means the global climate system hasn't had time to reset to a cooler baseline between events.
Onset Speed: 2026 Is Faster
The 2026 El Niño has ramped from +0.6°C in March to +1.4°C in July — a rise of 0.8°C in four months. The 2023 event took six months (March to August) to cover the same ground. The faster onset in 2026 is being driven by more frequent and stronger westerly wind bursts — five significant events since March vs. three in the same period in 2023. Each burst acts like a pump, pushing warm surface water from the western Pacific toward South America.
Faster onset doesn't necessarily mean a higher peak — 1997 ramped extremely fast, 2015 was more gradual, and both reached similar peak intensities. But it does mean less lead time for seasonal forecasts and preparedness. By the time some sectors (agriculture, water management, disaster response) are fully mobilized, the event may already be in its intensification phase.
Why the Context Matters More Than the Numbers
Even if the 2026 and 2023-24 events end up peaking at similar Niño-3.4 values, the impacts won't be the same. The world is warmer now. The 1.52°C above pre-industrial baseline in the first half of 2026 compares to 1.36°C at the same point in 2023. That 0.16°C difference might sound small, but it means the same Niño-3.4 anomaly produces higher absolute temperatures — hot extremes are hotter, marine heatwaves are more severe, and the margin before ecosystems hit their breaking point is thinner.
There's also a compounding effect from the short gap between events. In 2023, southern Africa was deep in drought and the Amazon was experiencing low river levels after three La Niña years — but the agricultural and ecological systems hadn't been hit by a strong El Niño since 2015-16. In 2026, some of those same systems are still recovering from the 2023-24 event. A second strong El Niño so soon means less resilience, less stored water, thinner financial buffers for farmers, and ecosystems pushed closer to tipping points.
What 2023-24 Taught Us
The 2023-24 El Niño was a stress test for global preparedness, and some things worked better than expected. Forecasts were accurate and early — NOAA declared an El Niño Watch in April 2023 and an Advisory by June, giving 6+ months of lead time before the winter peak. The Panama Canal Authority had contingency plans for low lake levels. California's water managers had reservoir levels high going into the wet winter. Coral reef managers pre-deployed shading and cooling interventions in some locations.
But other lessons were harder. Heat-related deaths spiked globally — Europe alone recorded roughly 60,000 excess deaths during the summer of 2023, many heat-related. The 2023 Canadian wildfire season burned an area the size of Greece and sent smoke to New York and Madrid. Southern Africa's maize harvest dropped 30%, pushing millions toward food insecurity. Those lessons should inform 2026 preparedness, but many countries haven't had time to implement them.
The Compounding Risk Problem
The shortest gap between strong El Niños since 1950 was the 1963-65 sequence: a moderate event in 1963 was followed by a strong El Niño in 1965, with only a brief neutral period in between. The 2023-24 to 2026 sequence looks similar or more extreme. If the 2026 event reaches +1.5°C or higher, it will be the first time two El Niños of that magnitude have occurred within three years in the modern record.
Climate models disagree on whether this faster cycling is a harbinger of things to come. Some project that under warming, extreme El Niños will become more frequent; others argue the opposite — that a warmer Pacific will actually stabilize the Walker Circulation and reduce ENSO variability. The 2026 event won't settle the debate, but it will add a significant data point.