Super El Niño events

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Global climate phenomenon

Super El Niño events, also called very strong El Niño events, are climatic phenomena resulting from the average sea surface temperatures in parts of the Pacific Ocean rising by 2° Celsius or more, affecting global weather patterns. Impacts can include widespread and severe flooding and drought and unseasonable temperature extremes, which can result in crop failures, food shortages, famine, disruption in water supplies, displacement, declines in native fauna, and an increased risk of wildfires and cyclones, which can contribute to economic disruption and civil conflict. As of early 2026 there have been five super El Niño events in recorded history. El Niño events prior to modern recordkeeping are sometimes identified by paleoclimatologists, historians and archeologists and are referred to as Mega-Niños.

El Niño is a natural climate event caused by the El Niño-Southern Oscillation (ENSO),^[1] through which warming of the eastern equatorial Pacific Ocean results in the development of unusually warm waters between the coast of South America and the International Date Line. This phenomenon significantly affects the global average surface temperature of the planet. A large El Niño event can raise it by as much as a few tenths of a degree Celsius.^[2]

A super El Niño occurs when the average sea surface temperatures (SST) in parts of the Pacific rise by 2° centigrade or more, affecting global weather patterns.^[3][4][5] The term "super El Niño" was first used in 2003 to describe an event in which "the surface zonal wind stress, SST, and the equatorial upwelling anomales are proportionately large".^[6][7] The term is not an official designation of any agency but is an informal descriptor used by some forecasters; the NOAA's official terminology for 2° centigrade rise or more is "very strong El Niño".^[5]

Super El Niño events are not common, but have become more frequent from the last half of the 20th century.^[3][8] By the early 2020s scientists have predicted more frequent super El Niño events as variability in SSTs has increased since 1960.^[9][10][11]

Super El Niños can cause widespread and severe flooding and drought and unseasonable temperature extremes, which can result in crop failures, food shortages, famine, disruption of water supplies, temporary or permanent population displacement, declines in native fauna, an increased risk of wildfires, cyclones, and disease outbreaks, and can contribute to economic disruption and civil conflict.^{[4][12][13][11][14][10][15]: 77} They can also trigger climate regime shifts, lasting changes in weather patterns.^[12][16] Impact is often beyond the equatorial Pacific.^[17]

The strongest super El Niño on record as of early 2026 was the 1877–1878 event, which led to a global famine that killed more than 50 million people, or about 3-4 percent of the estimated global population, in disasters such as the Great Famine of 1876–1878 in India, the Northern Chinese Famine of 1876–1879, and the Grande Seca in Brazil.^[8] In North America the event was known as the Year without a winter because of unseasonably warm weather in certain areas.^{[18][19][20][21]}

The 1982–83 El Niño caused droughts in Africa, Indonesia and Australia, a warm winter in much of North America, Europe, and Asia, and heavy rains and flooding in South America.^[11] The event led to an upsurge in scientific interest in the phenomenon.^[11][8][13]

The 1997–1998 El Niño was regarded as one of the most powerful El Niño events in recorded history, resulting in widespread droughts, flooding and other natural disasters across the globe. It caused an estimated 16% of the world's reef systems to die, and temporarily warmed air temperature by 1.5 °C (2.7 °F) compared to the usual increase of 0.25 °C (0.45 °F) associated with El Niño events.^[22] The costs of the event were considerable, leading to global economic losses of US$5.7 trillion within five years.^[23] The 1997-1998 event increased public awareness and interest in the phenomenon.^[13] Global prediction models became available commercially.^[13]

The 2014–2016 El Niño developed from unusually warm waters developing between the coast of South America and the International Date Line. These unusually warm waters influenced the world's weather in a number of ways, which in turn significantly affected various parts of the world. These included drought conditions in Venezuela, Australia and a number of Pacific islands while significant flooding was also recorded. During the event, more tropical cyclones than normal occurred within the Pacific Ocean, while fewer than normal occurred in the Atlantic Ocean.^[24]

The 2023–2024 El Niño was regarded as the fifth-most powerful El Niño event in recorded history, resulting in widespread droughts, flooding and other natural disasters across the globe. The onset was declared on 4 July 2023 by the World Meteorological Organization (WMO).^{[25][26][27][28]} It caused droughts in southern Africa, flooding in Brazil, and contributed to 2024's record high temperatures.^[29]

The term Mega-Niño was coined by archeologist Betty Meggers in 1994 to describe El Niño events that caused major effects over the past two millennia prior to instrumental recordkeeping and which can be identified by paleoclimatogologists, historians and archeologists from contemporaneous accounts and geologic evidence.^{[15]: 76–77} A Mega-Niño is speculated to have contributed to the end-Permian extinction.^[30][31]