Japan declares start of El Niño as forecasters worldwide warn of strongest event in over a century
Japan's weather agency has made the first official declaration of El Niño's return, while other forecasters warn it could develop into the most powerful such event in over a century.
A declaration and converging forecasts
Japan's Meteorological Agency officially declared El Niño conditions on 10 June, becoming the first major weather organization to do so. NOAA earlier estimated an 82% chance of the event emerging this month, with an updated forecast expected on Thursday. The World Meteorological Organization sees an 80% probability between June and August, and at least a 90% chance the episode persists until November. Copernicus director Carlo Buontempo said all models raised their forecasts between 1 May and 1 June, and probabilities lean toward a moderate to strong or possibly unprecedented event.
From 1 May to 1 June, all models revised their forecasts upward. The probabilities strongly favor a moderate to strong episode, or probably strong to potentially unprecedented at this stage.
The world must treat it as the urgent climate warning it is. El Niño conditions will pour fuel on the fire of a warming world.
What is driving the alarm
The defining signal is an abnormal warming of sea surface temperatures in the central and eastern equatorial Pacific. NOAA requires Niño-3.4 temperatures to stay at least 0.5°C above average for five overlapping three-month periods before it formally declares El Niño, a threshold not yet met in the United States. But atmospheric signs are already aligning: weakened trade winds, shifts in rainfall and cloudiness, and increased tropical storm activity in the eastern Pacific, with three named storms forming in just 10 days. The European Centre for Medium-Range Weather Forecasts projects temperature rises of 2.5°C to 4°C in the key region, well above the 2°C threshold that defines a "super El Niño." Paul Roundy of the State University of New York at Albany said there is "real potential for the strongest El Niño event in 140 years."
- World Meteorological Organization issues alert of high El Niño probability
- NOAA estimates 82% chance of El Niño emerging in June
- Tropical Storm Boris makes landfall on Mexico's Pacific coast
- Japan Meteorological Agency officially declares the onset of El Niño
- NOAA expected to release updated El Niño forecast
How the world could be affected
El Niño reshapes global weather by altering atmospheric circulation. Drought risk rises in parts of Central America, Asia, Africa, and Australia, threatening agriculture, hydropower, and drinking water. In Honduras, authorities estimate about 75 municipalities could face severe drought and the capital Tegucigalpa has already declared a water emergency. Conversely, other regions including the southern United States and parts of South America face increased flood hazard. The phenomenon also fuels heatwaves and extreme temperatures; the last El Niño in 2023–2024 contributed to making those years the hottest on record. Economic costs from past strong events have run into trillions of dollars, and the current one, unfolding in a climate already warmed by human activity, risks amplifying extremes further.
Rare event, heightened caution
Super El Niños are uncommon; experts note only four comparable episodes since the 1950s, roughly one every 10 to 15 years. The previous benchmarks of 1982–1983, 1997–1998, and 2015–2016 each brought devastating droughts, floods, and crop failures. Belgian climatologist Wim Thiery cautions that the precise trajectory remains uncertain but acknowledges the elevated risk. The World Meteorological Organization underscores that even natural variability now interacts with a warmer baseline from greenhouse gas emissions, making the consequences more severe.
