What is a 'super El Nino' and how will it affect the weather?

An El Nino building in the Pacific Ocean is on course to become one of the strongest on record, raising the risk of floods, droughts, extreme heat and crop losses across the world well into 2027.

The World Meteorological Organization (WMO) said on September 3 that El Nino is firmly established and will become very strong before peaking towards the end of this year. It said there is a near 100 per cent chance the event will last through February 2027.

The US National Oceanic and Atmospheric Administration (NOAA) said on September 10 that there is a more than 90 per cent chance of a very strong event this autumn and winter. It also gave a 75 per cent chance that the event will be stronger than any El Nino on record since 1950 during October to December.


"El Nino is being supersized before our eyes," UN Secretary-General Antonio Guterres said in the WMO release.

What is a "super" El Nino?

El Nino is the warm phase of a natural climate cycle in the Pacific, marked by warmer-than-normal sea surface temperatures in the central and eastern equatorial Pacific, WMO said. It occurs every two to seven years and usually peaks between November and February.

"Super" is an informal term. WMO does not use it and classifies events as weak, moderate, strong or very strong, depending on how far Pacific sea temperatures rise above normal. A rise of 2.0 degrees Celsius or more counts as very strong.

The International Research Institute for Climate and Society at Columbia University said the weekly reading in the key Nino 3.4 region of the Pacific reached +3.0 degrees Celsius in mid-September. All 22 forecast models it tracks show a very strong event through winter.

How dangerous is the heat?

WMO said El Nino is a natural phenomenon and is not caused by climate change. The Climate Impact Lab at the University of Chicago, however, projects that global land temperatures will run 1.2 degrees Celsius above normal in the coming months, with 44 per cent more extremely hot days than in a normal year.

The lab estimates 451,000 additional heat-related deaths worldwide from June 2026 to February 2027, compared with a normal year. These are modelled projections, not recorded deaths. Between September and February, it projects 31,400 additional deaths in Nigeria, 19,300 in Indonesia, 17,500 in Sudan and 15,800 in India.

The lab said measures such as heat warnings and cooling centres could save tens of thousands of lives.

What does it mean for India?

The India Meteorological Department (IMD) had forecast in May that the monsoon would bring 90 per cent of the long period average rainfall, citing El Nino. IMD data showed an all-India rainfall deficit of 15 per cent as of September 13, with the south peninsula 28 per cent below normal.

Rice exporters expect India's harvest, the world's top producer, to fall this year by the most since 2009-10, when an El Nino-linked drought hit output.

The Climate Impact Lab expects heat-related deaths in India and Pakistan to keep rising into next summer. WMO has forecast above-normal temperatures across almost all land areas from September to November.

What about the rest of the world?

El Nino typically brings heavier rain to southern South America and parts of Central Asia, and dries out southern Africa, Central America and Australia, threatening crops. In 2024, floods in Brazil's Rio Grande do Sul state killed more than 180 people and displaced 600,000, Reuters reported.

The UN World Food Programme said El Nino could push 49 million more people into acute hunger by the end of 2027, with Central America and southern Africa among the worst hit.

WMO said the impacts will continue well into 2027 and that it has launched its biggest ever mobilisation with national weather services to support early warnings. NOAA's next update is due on October 8.

(With inputs from Reuters)