What Is El Niño? The Meaning, Origin and Impact on South Africa

El Niño is a natural climate pattern in which the surface of the central and eastern tropical Pacific Ocean becomes unusually warm. The warming shifts winds and rainfall around the world. For South Africa, El Niño usually means a hotter, drier summer in the summer rainfall region. It returns every two to seven years and typically lasts nine to twelve months.

With the South African Weather Service (SAWS) warning that the 2026/27 El Niño could be exceptionally strong, it is worth understanding what El Niño (often written El Nino) actually is, where it comes from, and what it does and does not mean for your farm.

What does "El Niño" mean?

El Niño is Spanish for "the little boy". In the original usage it referred to El Niño de Navidad, the Christ child.

The name comes from fishermen on the coasts of Peru and Ecuador, who noticed that every few years a warm ocean current arrived around Christmas time. The warm water drove away the cold, nutrient-rich water that their anchovy and sardine catches depended on, so fishing collapsed in those years. They named the current after the season in which it appeared.

Its cooler opposite was later named La Niña, "the little girl".

Where did El Niño originate? A short history

El Niño is not new, and it was not invented by modern climate science.

• 1600s: Fishermen off the west coast of South America were already recognising the unusual warm-water years, according to the US National Oceanic and Atmospheric Administration (NOAA).
• 1892: Peruvian navy captain Camilo Carrillo described the warm "El Niño" current to the Geographical Society of Lima. This is one of the first scientific references to it.
• 1920s: British scientist Sir Gilbert Walker, working in India to predict monsoon failures, discovered a see-saw in air pressure between the eastern and western Pacific. When pressure rose on one side, it fell on the other. He called it the Southern Oscillation.
• 1969: Norwegian-American meteorologist Jacob Bjerknes showed that the warm ocean current and Walker's pressure see-saw were two halves of the same system. Scientists now call the combined phenomenon ENSO: the El Niño-Southern Oscillation.

So, geographically, El Niño originates in the tropical Pacific Ocean, along the equator between the International Date Line and the coast of South America. It was first noticed off Peru and Ecuador, but its effects reach almost every continent, including southern Africa.

How does El Niño work?

Normal conditions

In a normal year, the trade winds blow from east to west along the equator in the Pacific. They push warm surface water towards Indonesia and Australia, where it piles up in a "warm pool". Off South America, cold, nutrient-rich water rises from the deep to replace it (a process called upwelling). Warm water in the west means rising air, clouds and heavy rain over Indonesia, and drier conditions over the eastern Pacific.

During El Niño

During an El Niño, the trade winds weaken, and sometimes reverse. The warm water sloshes back east across the Pacific. Upwelling off South America weakens, the eastern Pacific warms, and the zone of rising air and heavy rainfall moves east with the warm water.

Because the tropical Pacific is so large, that shift redirects atmospheric circulation over much of the planet. Some regions get floods; others get drought. Scientists call these long-distance effects teleconnections.

La Niña: the opposite phase

La Niña is the reverse. The trade winds strengthen, the eastern Pacific becomes cooler than normal, and the warm pool is pushed even further west. Between El Niño and La Niña are neutral years. For South Africa, La Niña summers tend to be wetter than normal.

	El Niño	La Niña
Pacific Ocean (central/east)	Warmer than normal	Cooler than normal
Trade winds	Weaker	Stronger
Typical SA summer rainfall	Below normal	Above normal
Typical SA summer temperatures	Hotter	Milder

How is El Niño measured?

Forecasters watch a patch of ocean called the Niño 3.4 region, in the central-eastern equatorial Pacific. NOAA declares El Niño conditions when sea surface temperatures there are at least 0.5 °C above average for a sustained period, together with matching changes in the atmosphere. Above roughly 1.5 °C, an event is usually described as strong. In September 2026, Farmer's Weekly reported that Pacific temperatures could rise more than 3 °C above average during the current event.

What does El Niño mean for South Africa?

South Africa is far from the Pacific, but El Niño shifts the weather systems that bring our summer rain. In an El Niño summer, the summer rainfall region, which covers most of the interior, the Highveld, the Free State, North West, Mpumalanga, Limpopo and KwaZulu-Natal, tends to be:

• Drier, with rain arriving later or in fewer, heavier storms and longer dry spells.
• Hotter, which increases evaporation and crop stress even when rain does fall.

That matters for maize, sunflower, soybeans, grazing and dam levels. The winter rainfall region of the Western Cape is less directly linked to El Niño.

Past El Niño droughts in South Africa

• 1982/83: A very strong El Niño and widespread drought.
• 1991/92: One of southern Africa's worst droughts in living memory.
• 2015/16: A very strong El Niño and widespread drought. SAWS recorded 2015 as South Africa's driest year since national records began in 1904, and the 2016 commercial maize crop fell to roughly 7.8 million tonnes, about half of a normal harvest.

El Niño does not guarantee drought

The 1997/98 El Niño was one of the strongest on record, yet parts of the summer rainfall region received slightly above-normal rain. SAWS and the National Disaster Management Centre stress that the strength of an El Niño "should not be interpreted as a direct indication of the magnitude or spatial distribution of impacts." El Niño shifts the odds towards a hot, dry summer. It does not decide your farm's rainfall on its own.

El Niño 2026/27: the current forecast

• SAWS confirmed on 1 September 2026 that El Niño is strong and likely to intensify, with a peak expected in late 2026 or early 2027.
• University of Pretoria climate scientist Prof Willem Landman described it as "a mature coupled ocean-atmosphere phenomenon" that is "rapidly intensifying".
• SAWS forecasts point to below-normal rainfall over most of the country for October to December 2026, with a similar pattern for November 2026 to January 2027, and above-normal temperatures throughout.
• The Agricultural Research Council expects reduced grazing and lower summer grain yields, and advises that "a conservative management strategy is advised during El Niño summers."

There is some good news: authorities note that agricultural conditions going into this summer are more favourable than they were before the 2015/16 drought, although that can change as the season unfolds.

How farmers can prepare for El Niño

The Department of Agriculture and the experts quoted by Farmer's Weekly recommend that producers:

1. Follow SAWS seasonal and short-range forecasts, and combine them with what you see on your own farm.
2. Conserve soil moisture with minimum tillage, mulching and residue cover.
3. Reassess planting windows and cultivars. Consider shorter-season or more drought-tolerant options.
4. Watch the signals that matter: when the rain starts, how it is spread, how long dry spells last, and when the season ends.
5. Adjust stocking rates and grazing plans to realistic veld carrying capacity, and secure livestock water early.
6. Manage water use strategically. Check dam and borehole levels, and fix leaks.

For a deeper look at the season ahead, read our guide to planning the 2026/27 season.

Frequently asked questions about El Niño

What is El Niño in simple terms? El Niño is a periodic warming of the surface of the central and eastern tropical Pacific Ocean. It changes wind and rainfall patterns worldwide, and in South Africa it usually brings a hotter, drier summer.

Where does El Niño come from? El Niño originates in the tropical Pacific Ocean along the equator. It was first noticed by fishermen off Peru and Ecuador, who saw warm water arrive around Christmas.

Why is it called El Niño? El Niño means "the little boy" in Spanish and refers to the Christ child, because the warm current appeared around Christmas.

What is the difference between El Niño and La Niña? El Niño is the warm phase, when the eastern Pacific is warmer than normal. La Niña is the cool phase. In South Africa, El Niño tends to bring drier summers and La Niña wetter summers.

How often does El Niño happen? Roughly every two to seven years. An event usually lasts nine to twelve months.

Does El Niño always cause drought in South Africa? No. It increases the chance of a hot, dry summer in the summer rainfall region, but it does not guarantee drought. The strong 1997/98 El Niño brought near-normal or slightly above-normal rain to parts of the country.

Is there an El Niño in 2026? Yes. SAWS confirmed a strong El Niño in September 2026 and expects it to peak in late 2026 or early 2027, with below-normal rainfall and above-normal temperatures likely over much of South Africa.

What is ENSO? ENSO stands for El Niño-Southern Oscillation: the linked ocean (El Niño/La Niña) and atmosphere (Southern Oscillation) cycle in the tropical Pacific.