El Niño 2026-27: a forecast, not yet a verdict

El Niño is a warming of the central and eastern tropical Pacific Ocean that shifts weather patterns worldwide, and in 2026 it returned with force. The World Meteorological Organization said on 3 September 2026 that El Niño was firmly established and forecast to strengthen further, with nearly 100 per cent likelihood of persistence through February 2027. The WMO cautioned, however, that the strength of an El Niño event does not translate directly into the magnitude of impacts in any particular country, a warning that matters for India, where El Niño years are often associated with weaker monsoons but not always.

The connection to India runs through two channels: rain and heat. IMD's director general attributed the below-normal cyclone activity of 2026 partly to strong El Niño conditions, which tend to reduce cyclone numbers over the Bay of Bengal and the Arabian Sea. On heat, a Climate Impact Lab assessment estimated about 15,800 additional heat-related deaths in India between September 2026 and February 2027 compared with a normal year, with an uncertainty of roughly 1,600 deaths, and nearly half of those, about 7,400, projected between December and February. The estimate is a projection based on temperature-mortality relationships, not a record of deaths already occurring, and the same assessment put the global figure at about 239,000 additional deaths.

A 2026 study from the Indian Institute of Tropical Meteorology added a practical tool. Its researchers found that El Niño–Southern Oscillation signals could help anticipate the risk of extreme humid heat in India up to six months in advance, explaining about 42 per cent of the variation in India, and could predict summer labour productivity losses, measured as time lost because workers must slow down, take rest breaks, or stop work to prevent heat hazards. India already issues seasonal temperature and heatwave outlooks and an experimental five-day heat-index forecast, which inform heat action plans across 23 states.

The discipline for readers is to keep three things separate: the observed ocean state, which is firmly established; the modelled impacts, which carry uncertainty; and the policy response, which can be prepared before either is certain. Forecasts are most useful when they trigger preparation, such as water planning, health surveillance, and adjusted working hours, rather than when they are quoted later as if they were facts.