The World Meteorological Organization (WMO) has confirmed a marked and accelerating shift in Pacific Ocean conditions that points to the development of El Niño heading into the second half of 2026, prompting renewed warnings for Pacific Island communities to prepare for altered rainfall, drought and marine conditions. The agency’s latest El Niño/La Niña Update, produced with the International Research Institute for Climate and Society (IRI) and global modelling centres, says there is now high model agreement that El Niño is forming.
United Nations Secretary‑General António Guterres amplified the alert in a video statement, saying there is a 90 percent certainty that El Niño will arrive in the coming months and urging global action. “El Niño conditions will pour fuel on the fire of a warming world,” he said, warning the phenomenon could intensify heatwaves, disrupt food and water supplies and exacerbate extreme weather across borders. WMO Secretary‑General Celeste Saulo added that the 2023–24 El Niño was among the five strongest on record and underlined that another strong event would heighten the risk of drought, heavy rainfall and ocean heatwaves.
The scientific signals underpinning the WMO’s assessment are concrete and recent. Observations from late April through mid‑May show sea surface temperature anomalies in the central‑eastern equatorial Pacific approaching the thresholds used to define El Niño. Those surface anomalies are being fed by an unusually warm subsurface reservoir in the tropical Pacific, with subsurface temperatures exceeding 6°C above average in places — a substantial source of heat that can rapidly translate into surface warming. The Southern Oscillation Index, the atmospheric component of ENSO, is also trending in a direction consistent with developing El Niño conditions.
For Pacific governments and communities, the update represents a change in forecast trajectory. In early 2025 forecasters were watching for La Niña to weaken and for a return to ENSO‑neutral conditions, with only a low chance projected then of El Niño forming. The new WMO consensus and the strong subsurface heat signal mark a clear shift from those earlier outlooks and increase the urgency of seasonal planning for agriculture, water resources, health services and fisheries.
Regional climate authorities are pressing for locally tailored guidance. Dr Simon McGree, chair of the Pacific Regional Climate Centre (Pacific RCC) Management Committee, said a regional El Niño forecast is only a starting point and stressed the pronounced variability of impacts across Melanesia, Polynesia and Micronesia. “Climate impacts play out differently across the Pacific … Local National Meteorological and Hydrological Services can provide the place‑based outlooks people need to make practical decisions,” he said. The Pacific RCC is urging communities, local leaders and planners to consult their national services for seasonal forecasts and early warnings.
The WMO said it and its partners will be closely monitoring conditions in the coming months to refine forecasts and inform governments, humanitarian agencies and climate‑sensitive sectors. The organisation reiterated that advance seasonal forecasts and early warning systems are vital to save lives and reduce economic losses, while regional leaders — including those who have repeatedly called for greater climate finance and support for Small Island Developing States — say preparedness and resourcing must be accelerated in light of the heightened risk.