UN warns El Niño will rapidly strengthen to a strong event by September, raising global extreme weather risks
The World Meteorological Organization says a strong El Niño is now virtually certain to develop by September, increasing the probability of heatwaves, droughts and heavy rainfall worldwide.
The forecast
El Niño conditions have already emerged in the tropical Pacific and will intensify rapidly into a strong event between July and September, the World Meteorological Organization (WMO) warned on Friday. The agency now expects the phenomenon to reach level 3 on its 4-level scale, a marked upgrade from its June outlook which had pointed to a moderate or possibly strong episode.
The El Niño phenomenon is already present and should intensify rapidly, reaching a strong intensity.
Forecast models show a consistent and significant warming of ocean temperatures across the central and eastern equatorial Pacific, with seasonal-average sea-surface temperature anomalies expected to exceed 2 °C in key monitoring regions. The WMO said it may revise the forecast upward again later this summer if data point to a very strong event.
- El Niño begins, according to NOAA confirmation on June 11
- WMO warns of imminent El Niño, forecasts moderate or possibly strong event
- NOAA confirms El Niño started in May
- WMO updates forecast: rapid intensification to strong El Niño (level 3/4) between July and September
- Typical peak period for El Niño intensity
- Impacts expected to continue into 2027
Regional impacts
Typical strong El Niño patterns are emerging in seasonal outlooks. Central America, the Caribbean, and parts of South America face drier than normal conditions, while South Asia’s monsoon, Indonesia and Southeast Asia are also projected to see reduced rainfall. Northern Europe is forecast to be drier than average, whereas southern Europe and the southwestern United States are likely to receive more precipitation, though the European predictions carry greater uncertainty.
In Peru, nearly 800 municipalities have already been declared under a state of emergency because of the “imminent danger” of intense rainfall, with over 9.3 million people exposed to very high risk from floods and landslides linked to the phenomenon.
Heat and global temperatures
El Niño normally gives global temperatures an extra boost. Scientist Alvaro Silva of the WMO noted that during El Niño years temperatures typically reach record levels. The last episode, in 2023 and 2024, helped drive those years to become the two hottest on record, and 2024 ended around 1.55 °C above the 1850–1900 pre-industrial average.
We know that during El Niño years the global temperatures normally reach record levels.
The warming influence of this El Niño is expected to persist well beyond its typical November-to-February peak, with impacts felt in different regions until the end of 2026 and into 2027.
Europe’s recent heatwave
Europe just experienced its worst recorded heatwave between June 20 and 28, disrupting power generation, damaging infrastructure and overwhelming healthcare systems. Scientists said the extreme heat was almost certainly driven by climate change, a backdrop that makes the developing El Niño especially concerning.
