WMO forecasts record El Niño sea-temperature anomaly; Greater Horn of Africa likely wetter than normal

The World Meteorological Organization (WMO) forecast on 8 October that the Niño 3.4 sea-surface temperature anomaly will reach about +3.7°C as a seasonal average in October–December 2026, peaking around December. The WMO said this is the highest since observations began and is stronger than the previous record of +2.6°C, set in November 2015–January 2016. The figure is a forecast, not a measurement.

The Niño 3.4 index tracks sea-surface temperature anomalies in the central-eastern equatorial Pacific, the region at the heart of El Niño. The index averaged +1.6°C above normal in June 2026 and +2.5°C above normal in August. Global sea-surface temperature reached an all-time observed high in August.

WMO Secretary-General Celeste Saulo said in the WMO statement: "El Niño is firmly established and strengthening rapidly. WMO forecasts indicate a near-100 per cent likelihood that it will persist through February 2027, potentially being one of the strongest since at least 1950."

The WMO said that near-certainty is not the output of one model but a consensus across 13 national and international centres, from Washington to Tokyo, London and Pune, "built on real-time exchange of ocean buoy, satellite and radiosonde data coordinated by WMO".

Saulo also said: "El Niño doesn't add new heat to the planet. It releases heat the ocean has already been storing beneath the surface - which is why a strong event so often becomes one of the hottest years measured (as with 2024)."

For East Africa, wetter-than-normal conditions are more likely across the Greater Horn of Africa. The same is true of parts of Central Asia and coastal East Asia, the northern Arabian Peninsula, parts of North America south of 45°N and southeastern South America. Drier-than-normal conditions are forecast over the Indian subcontinent, southern Central America and parts of the Caribbean, and northwestern South America.

A positive Indian Ocean Dipole, a climate pattern that can strongly influence rainfall around the Indian Ocean, is expected to peak in October and then decline. Its October–December seasonal anomaly is forecast at about +0.5°C. El Niño is likely to bring above-average temperatures to much of the globe.

The WMO added that these signals describe where wetter- or drier-than-normal seasonal conditions are more likely, and "are not a substitute for national and local forecasts". Capital FM reported on 8 October that the WMO urged countries to use the forecasts to strengthen preparedness and risk management.

Kenya's own outlook for the October–December "short rains" was issued earlier, on 31 August 2026, by the Kenya Meteorological Service Authority. It expects above-average rainfall in counties including Nairobi, Mombasa, Kisumu, Nakuru, Garissa, Wajir and Mandera, and in much of West Pokot, Samburu and Marsabit counties. Capital FM reported on 26 August that the authority projected above-average rainfall across 80 per cent of the country.

Near-average to above-average rainfall is likely in Turkana and a few parts of West Pokot, Samburu and Marsabit. Mean temperatures are predicted to be warmer than average, with higher probabilities over Kwale, Mombasa, Kilifi, Lamu and parts of Tana River, Taita/Taveta and Garissa counties.

The authority also reviewed the previous season: most parts of Kenya received below-average rainfall in June–August 2026.