Teleconnections: The Pacific Butterfly Effect
El Niño’s remote impacts are transmitted through atmospheric teleconnections. The anomalous warm water in the equatorial Pacific drives deep convection eastward, releasing vast amounts of latent heat into the tropical atmosphere and exciting Rossby wave trains that propagate from the tropics to mid- and high latitudes. These waves alter the global jet stream paths, storm tracks, and precipitation patterns.
Regional Impacts
Hover over the map markers to see details for each region.
China
China — Southern Floods, Northern Drought
El Niño influences the East Asian Monsoon and the position of the subtropical high, typically producing a “southern floods, northern drought” pattern in China: more rain and higher flood risk along the Yangtze River basin and southern China; reduced rainfall and heat drought in the north and northeast.
1998 catastrophic Yangtze River basin flood
Impacts: flooding, heatwaves, agricultural losses
India
India — Weakened Monsoon
El Niño shows a strong negative correlation with Indian summer monsoon rainfall. In roughly 80% of El Niño years, Indian monsoon rainfall falls below normal. Agriculture (15% of GDP) is severely affected, with crop failures pushing up inflation.
~80% of El Niño years bring drought to India
Indonesia
Indonesia — Drought & Wildfires
During El Niño, deep convection migrates eastward away from the western Pacific warm pool, depriving Indonesia of its main rainfall source and causing severe drought. The 2015–16 event burned over 2.6 million hectares of forest, with transboundary haze affecting Singapore and Malaysia.
2015–16 wildfire area >2.6 million ha
Australia
Australia — Drought & Bushfires
El Niño sharply reduces rainfall across eastern and northern Australia, leaving vegetation extremely dry. The 2019–20 “Black Summer” bushfire season was driven by persistent drought conditions, burning over 24 million hectares.
2019–20 Black Summer: 24 million ha burned
Peru · Ecuador
Peru · Ecuador — Flooding & Fishery Collapse
The direct strike zone of El Niño. Warm water approaches the South American west coast; during 1997–98, rainfall in northern Peru reached more than 10 times the normal level. Meanwhile, warm water suppresses upwelling, and anchovy catches collapsed from 12 million tons to 2 million tons.
1997–98 Peru losses ~$3.5 billion
1972–73 fish catch dropped >80%
Brazil
Northeast Brazil — Drought
El Niño shifts the Walker Circulation eastward, placing northeast Brazil under anomalous subsiding air that sharply reduces rainy-season rainfall. Historically, several severe droughts coincided with strong El Niño events, leading to crop failure and famine.
Impacts: crop failure, water crisis
U.S. South
U.S. South — Wet & Cool · Hurricane Suppression
During El Niño, the jet stream shifts southward, channeling Pacific moisture across the southern U.S. from California to Florida, producing wetter and cooler conditions. Concurrently, eastern Pacific warming strengthens Atlantic wind shear, suppressing hurricane formation.
Increased California rainfall eases drought
Atlantic hurricane counts significantly reduced
Southern Africa
Southern Africa — Severe Drought
El Niño warm events show a strong negative correlation with summer rainfall in southern Africa. The 2015–16 super El Niño caused severe drought in South Africa, Zimbabwe, Zambia and other countries, leaving tens of millions facing food shortages.
2015–16: tens of millions in food crisis
East Africa
East Africa — Abnormally Wet
El Niño typically brings above-normal October–December short rains to East African countries including Kenya, Somalia, and Ethiopia. The 1997–98 event caused severe flooding in multiple areas, bringing both benefits and costs.
Impacts: flooding, landslides
Global Mean Temperature
During El Niño events, the tropical Pacific releases vast amounts of heat to the atmosphere, raising the global mean surface temperature by 0.1–0.2°C in the short term. As a result, the hottest years on record often coincide with strong El Niño events. The year 2016 (boosted by the 2015–16 super El Niño) held the “hottest year on record” title for an extended period.
Summary of Economic Impacts
| Event | Global Economic Loss | Main Affected Regions |
|---|---|---|
| 1982–83 | ~$8.1 billion | Peru, Ecuador, Indonesia, Australia, United States |
| 1997–98 | ~$96 billion | Worldwide, Peru/Ecuador hardest hit |
| 2015–16 | ~$60 billion | Southeast Asia, Southern Africa, South America, United States |
| 2023–24 | Assessing | South America, Horn of Africa, Southeast Asia |