In the weeks leading up to its expected December peak, the current El Niño is breaking temperature records that were set during the very strong 2015 event. Australia’s Bureau of Meteorology (BOM) reports that average weekly sea‑surface temperatures in the central Pacific have reached the highest values ever measured, while daily records in the central‑eastern Pacific were also surpassed earlier this September.
What the data show
Measurements taken from the equatorial Pacific – the region traditionally used to monitor El Niño – reveal several striking anomalies:
- Average weekly sea‑surface temperatures are now higher than any previous reading since the BOM began tracking data in 2008.
- Temperatures above 30 °C have been recorded for the first time in parts of the tropical Pacific.
- Record sea‑surface temperature anomalies and unusually warm subsurface layers have been observed across a broader swath of the Pacific than in past events.
Dr Zeke Hausfather of Berkeley Earth told the BBC, "We are currently witnessing an El Niño event that is unprecedented in the historical record," underscoring the scale of the anomaly.
El Niño in a warming world
El Niño is a natural climate pattern that recurs every two to seven years and typically lasts about a year. However, the background warming of the oceans caused by human‑driven climate change is now interwoven with the natural signal. To isolate the El Niño contribution, forecasters are using a Relative Ocean El Niño Index (RONI), which compares current temperatures against a baseline that removes the long‑term warming trend.Even after accounting for this baseline, the current event exceeds the 2015 benchmark, suggesting that the natural El Niño amplification is unusually strong. The World Meteorological Organization (WMO) cautions that there is still no definitive evidence that climate change is making El Niño events more intense or more frequent, though the topic remains under active investigation.
Potential global impacts
El Niño’s influence is already being felt, with early reports of drought and flood disruptions in East Africa and the Asia‑Pacific region. Historically, El Niño years see higher global temperatures than neutral years, and when combined with the ongoing trend of anthropogenic warming, 2026 is poised to be among the warmest years on record.
Key patterns that often accompany strong El Niño events include:
- Drought and wildfire risk in southeast Asia, reminiscent of the 1997‑98 and 2026 events.
- Flooding in parts of East Africa, echoing past severe flood episodes.
- Altered tropical cyclone activity: suppression of Atlantic hurricanes and a boost in Pacific cyclone formation.
These trends raise concerns about food security, especially in regions already vulnerable to climate extremes.
Uncertainty and next steps
While the temperature records are clear, the translation of these oceanic signals into specific regional weather outcomes carries uncertainty. Forecasts from the European Centre for Medium‑Range Weather Forecasts (ECMWF) and the U.S. National Oceanic and Atmospheric Administration (NOAA) agree that the El Niño will likely peak in December, but the exact timing and intensity of downstream effects—such as drought severity or flood magnitude—remain difficult to pin down.
Scientists continue to refine the RONI and other metrics to better compare this event with historic super El Niños (1972‑73, 1982‑83, 1997‑98, 2015‑16). Ongoing monitoring will be essential to discern how much of the observed warmth is attributable to the natural El Niño cycle versus the broader, human‑driven warming of the oceans.
Conclusion
The 2026 El Niño is setting new temperature benchmarks in the central Pacific, surpassing the record‑setting 2015 event. Its unprecedented warmth is already influencing weather patterns worldwide, but the precise scale of future impacts—especially on agriculture, water resources, and disaster risk—remains uncertain. Continued observation and improved modeling will be crucial for navigating the challenges posed by this historic climate episode.