Key probability thresholds from official forecasts:
Climate scientist Zeke Hausfather, reviewing 667 ensemble members from 14 different seasonal forecast models in July, described the outlook as a "potential record-smashing El Niño event" that "may end up the strongest by a truly mind-blowing margin" .
Several researchers told Nature on July 23 that the event is "on track to be the largest one in at least 150 years" . The European Commission's Joint Research Centre released an anticipatory analysis on July 16 warning that a record-strength event could have cascading global consequences across food security, water resources, and disaster risk .
The El Niño boost comes at a time when the planet is already exceptionally warm. The January–June 2026 global surface temperature departure was the third-highest in the 177-year record at +1.14°C above baseline, behind only 2024 and 2025 . The key question is whether the El Niño peak will arrive early enough in 2026 to lift the annual average above 2024's record, or whether that distinction will go to 2027.
Estimates vary by dataset and methodology:
The disparity stems from whether the El Niño peak arrives late enough in 2026 to fully register in the annual average or spills into early 2027. Hausfather noted the odds range from around two-in-three in NASA and Berkeley Earth data to around two-in-10 in ERA5 and one-in-10 in the JRA-3Q reanalysis .
Perhaps the most acute risk from the 2026 El Niño is to the Amazon rainforest, which enters this event already severely weakened from the 2023–2024 drought.
Compounding stress: A study published in PNAS in April 2026 found that 53.7% of intact rainforest areas affected by the 2023–2024 drought will still not have recovered even seven years later . The forest is losing biomass, which reduces its ability to recycle water and maintain its microclimate. INPE-led research published in July found that the Brazilian Amazon is already experiencing longer dry seasons and rainfall changes previously projected for the 2030s and 2040s, meaning the system's resilience is eroding faster than expected .
Heat and fire: During the 2023–2024 El Niño, temperatures in the Amazon rose 2–4°C (3.5–7°F) above the forest's historical average . A new super El Niño could push conditions past critical thresholds, with the drier northeastern Amazon, northern Brazil, Colombia, and Venezuela facing extreme wildfire risk and rapidly falling river levels .
Government response: Brazil has increased wildfire spending and hired a record number of federal firefighters in anticipation of extreme drought .
World Weather Attribution has warned that 2026 could see "an unprecedented year of global fire" as El Niño compounds existing heat and dryness .
Scientists across multiple fields stress that this is a layered crisis, not a purely natural one. El Niño is a natural cyclical phenomenon, but it is now unfolding on top of a ~1.3°C human-caused warming baseline. The result is that every El Niño event pushes global temperatures higher than any comparable event in the past .
The rapid return of El Niño — just three years after the last one — is itself unusual. Hansen's team suggests that extreme background warming may be altering the dynamics of the ENSO cycle itself . Climate change is also making El Niño's impacts less predictable. Australian Bureau of Meteorology experts noted in June that the consequences of El Niño are "becoming increasingly unpredictable due to climate change," with traditional teleconnection patterns breaking down .
The WMO and UN agencies have emphasized that while El Niño provides the temporary heat boost, it is the decades of anthropogenic warming that have locked in the record-breaking baseline, making even moderate El Niños dangerous .
A broad coalition of scientific bodies and international agencies has issued urgent warnings:
UN Secretary-General António Guterres added his voice to the calls, stating: "El Niño conditions will pour fuel on the fire of a warming world. Impacts will hit even harder, travel even farther, and cross borders with devastating speed" .
The 2026 El Niño is intensifying faster than almost any event on record, with an 81% chance of ranking among the top historical events and strong potential to reach super El Niño status. It has already raised the odds of 2026 surpassing 2024 as the hottest year to 35–50%, depending on the model, with 2027 an even stronger candidate. The Amazon, still recovering from the 2023–2024 drought, faces the most acute ecosystem risk, and scientists across climate, ecology, and humanitarian fields are issuing coordinated calls for urgent preparation before the event peaks near year's end.