El Niño and Drought: Global Impacts, Water & Crop Risks

Kenya experiences heightened rainfall and heightened flood hazards during El Niño events, particularly during the October–December short rains season. Teleconnections are intensified when positive Indian Ocean Dipole (IOD) anomalies coincide with Pacific warming.

Uganda is situated in the Lake Victoria basin, where El Niño typically enhances late-year rainfall, raising water levels and causing landslides in mountainous eastern regions.

Tanzania experiences elevated rainfall across its northern bimodal zones and coastal strip during El Niño, while central and southern unimodal regions occasionally face erratic distribution.

El Niño typically suppresses the vital Kiremt summer rains in the Ethiopian highlands, leading to drought, while conversely stimulating heavy late-year rains and flash floods in southeastern pastoralist lowlands (Somali Region).

Somalia is among the most vulnerable nations to El Niño: while pastoral areas suffer in dry phases, strong El Niño events historically deliver devastating deluges along the Juba and Shabelle rivers.

El Niño typically brings hot, dry conditions and agricultural drought to the summer rainfall regions of South Africa, depressing maize yields and stressing municipal water supplies.

Zimbabwe is exceptionally sensitive to El Niño: summer rainfall (November–March) is consistently suppressed, resulting in widespread crop failure, water shortages, and low Kariba hydropower generation.

Mozambique experiences a marked north-south divergence during El Niño: southern and central provinces frequently suffer from drought, while northern river basins can experience erratic, intense storm runoff.

El Niño has a historically strong correlation with deficient Indian Southwest Monsoon rainfall (June–September), frequently resulting in agricultural drought, though positive Indian Ocean Dipole (IOD) events can moderate its impact.

Indonesia sits at the western pole of the Pacific Walker Circulation. El Niño shifts ascending atmospheric motion eastward, causing suppressed rainfall, severe drought, and catastrophic peatland and forest fires.

The Philippines suffers from severe rainfall deficits, extended dry spells, and reservoir depletion during El Niño. Typhoon tracks also tend to form further east in the Pacific and recurve northward.

El Niño typically brings reduced winter and spring rainfall across eastern and northern Australia, warmer daytime temperatures, reduced tropical cyclone activity, and increased bushfire risk.

During El Niño, Japan frequently experiences milder winter temperatures and a tendency toward cloudier, cooler summers. The East Asian winter monsoon is generally weakened.

Peru is the epicentre of El Niño's historical discovery. Strong warming in Niño 1+2 waters collapses the Humboldt Current upwelling, disrupts the world's largest anchovy fishery, and triggers catastrophic desert downpours (huaycos) along the hyper-arid northern coast.

Ecuador's coastal plain and Galápagos Islands are exceptionally vulnerable to El Niño. Abnormal sea surface temperatures off the coast unleash heavy rain, triggering coastal river basin floods and extensive banana, shrimp, and cacao crop destruction.

Brazil exhibits a stark continental contrast during El Niño: northern and northeastern regions (including the Amazon and Sertão) suffer from severe drought and fires, while southern Brazil experiences excessive rainfall and catastrophic river flooding.

Colombia is typically characterized by suppressed rainfall, higher temperatures, and agricultural drought during El Niño, leading to stressed hydroelectric reservoirs (which supply ~70% of national power) and wildfire outbreaks.

Argentina experiences enhanced spring and summer precipitation across the fertile Pampas, Mesopotamia, and northeast during El Niño, supporting bumper crop yields but creating significant river flood risks along the Paraná and Uruguay basins.

El Niño impacts Mexico through a split pattern: winter precipitation is typically enhanced across northern desert and border states due to an intensified subtropical jet stream, while summer monsoon rains in southern and central Mexico are often suppressed.

In the United States, El Niño creates a classic dipole: the Pacific jet stream extends eastward, delivering storm after storm and above-normal winter precipitation across California, the Southwest, and the Gulf Coast, while the northern tier and Ohio Valley experience milder, drier winters.