Japan's weather agency declares El Niño conditions under way

On 10 June 2026 the Japan Meteorological Agency (JMA), the country's national weather service, announced that El Niño conditions had emerged in the tropical Pacific. The finding was based on its monitoring of ocean and atmospheric data, which showed sea surface temperatures off the coast of Peru running above normal.

El Niño is a periodic warming of the central and eastern tropical Pacific that shifts rainfall patterns and temperatures in many regions of the world. It is often linked to drought in some areas, flooding in others, and a rise in global average temperatures. The JMA issues regular assessments of the phenomenon, and its declaration is one of the recognised national signals that an event has begun.

The announcement mattered because it marked the start of what later became a closely watched episode. Forecasters, farmers, fisheries and energy planners use such declarations to prepare for changes in weather and commodity markets. The warming off Peru that the agency noted in June was an early sign of an event that, by October, was setting new temperature records in the same waters.