The El Niño warming of the equatorial Pacific is intensifying so rapidly that US federal forecasters now assess an 81 per cent probability it will reach the top “very strong” category by autumn, rivalling the historic 1997-98 event. Ocean temperatures in key monitoring zones are already at or near record highs for the time of year, partly because the natural cycle is compounding background warming from climate change. The US National Oceanic and Atmospheric Administration confirmed the system has moved past the weak stage and is now moderate, with no sign of slowing. Meteorologists in the United States and Europe note that the speed of the transition has shifted the global debate from whether the phenomenon will occur to its likely severity, persistence and timing.

That severity will be transmitted through two main channels: altered atmospheric circulation and direct physical impacts on water and temperature. A very strong El Niño increases the probability of a disrupted polar vortex during the northern winter, which can drive colder, snowier conditions across parts of the United States, Canada and Europe, according to long-range analysis by European severe-weather researchers. It also typically brings a rainier winter to the southern US and suppresses Atlantic hurricane activity. In the tropics, the mechanism is different: warming ocean surfaces shift rainfall patterns, intensifying drought in some regions and flooding in others. Energy researchers in Jakarta warn that reduced rainfall could cut water levels at hydroelectric dams, repeating the power-generation losses seen during the 2015 and 2023 El Niño episodes, while civil-society groups in Kalimantan are already pressing for an independent audit of grid reliability after recent blackouts.

Governments and markets are calibrating their responses to these projections. In Latin America, analysts at Morgan Stanley estimate that a severe episode could add up to 209 basis points to inflation in Peru, 168 in Brazil and 132 in Colombia, primarily through food and energy prices, with effects materialising from late 2026 into the first half of 2027. Colombia’s agriculture ministry has allocated more than 67 billion pesos to subsidise crop insurance, covering up to 85 per cent of premiums for smallholders, as the Ideam weather agency forecasts higher temperatures and reduced rainfall through early 2027. Mexico’s civil protection authority will launch a cell-phone alert system for cyclones and heavy rain within two months, while its meteorological service has issued monthly outlooks showing a wetter northern winter followed by extreme heat and fire risk in early 2027. In Brazil, Rio de Janeiro’s fire service has activated a six-level contingency plan for drought and forest fires, integrating state and municipal agencies.

The next factual milestone is the expected peak of the event during the boreal autumn and winter, when the accumulated heat in the Pacific is released into the atmosphere. Climate scientists in the US and Europe note that this could propel 2027 to a new global surface temperature record, surpassing the mark set during the last strong El Niño. For policymakers, the immediate watchpoints are the evolution of food and energy prices and the adequacy of grid and water infrastructure in vulnerable regions, as the phenomenon’s full economic and humanitarian footprint will be determined by its duration and the preparedness measures now being put in place.