A Climate Impact Lab tracker estimates 373,000 additional heat-related deaths worldwide from October 2026 through March 2027, with Nigeria's projected toll narrowly ahead of India's as El Niño strengthens.
The tracker puts the full June 2026-March 2027 period at 857,000 additional deaths. It estimates about 56,000 in Nigeria from October through March, compared with 55,000 in India, 29,000 in Indonesia and 19,000 in Brazil. The country figures are projections of additional deaths, not a count of confirmed fatalities.
The updated full-period projection exceeds the Lab's September estimate of 451,000 additional deaths through February. The Lab attributes most of the difference to adding March and to August and September temperatures running warmer than its earlier forecast. Its September report said projected heat mortality would fall most heavily on the Global South.
The World Meteorological Organization (WMO) said Oct. 8 that the Niño 3.4 sea-surface temperature anomaly is forecast to average about +3.7°C above normal during October-December and peak around December. It put the probability of El Niño continuing through February 2027 at nearly 100% and said the pattern is expected to affect weather and bring above-average temperatures to much of the world.
If reached, the anomaly would top the previous record of +2.6°C for November 2015-January 2016, WMO said. The agency said the event could rank among the strongest since at least 1950. WMO Secretary-General Celeste Saulo described El Niño as “firmly established and strengthening rapidly.”
The estimate pairs temperature records with mortality research for months that have passed, then uses seasonal projections for months ahead. ERA5 supplies the observed-temperature data; a 51-member forecast from the European Centre for Medium-Range Weather Forecasts (ECMWF) provides the outlook. The model also adjusts for local climate, vulnerability and capacity to adapt.
The Lab presents the tracker as a planning tool for measures such as heat alerts, medical care, water access and cooling locations. It plans monthly updates until El Niño ends. EconoTimes previously covered an earlier Nigeria heat-mortality forecast through February.
