El Niño Explained: What It Is, What Causes It and How We Can Reduce the Risks
This year’s ‘godzilla’ climate phenomenon has already broken temperature records. We ask a climate scientist what is happening
26 September 2026·8 min read·12
El Niño is one of the most important natural climate events in the world. It begins in the Pacific Ocean, but its effects can be felt in many countries across Africa, Asia, Europe and the Americas.
El Niño can change rainfall, temperatures, storms, farming conditions and even food prices. In some places, it can cause floods, while in others it can lead to drought.
The El Niño developing in 2026 is attracting a lot of attention because scientists expect it to become very strong.
What is El Niño?
El Niño is a natural climate event that happens when the surface water in the central and eastern Pacific Ocean becomes warmer than normal.
Normally, strong winds called trade winds blow from east to west across the Pacific Ocean.
These winds push warm water towards countries such as Indonesia and Australia.
At the same time, colder water rises from deep in the ocean near the coast of South America.
During El Niño, these trade winds become weaker.
As a result, warm water starts moving back towards the central and eastern Pacific.
The ocean becomes warmer in areas where it is usually cooler.
This change in ocean temperature also affects the atmosphere.
Rainfall, air pressure and wind patterns begin to change.
Because the ocean and atmosphere are connected, these changes can affect weather in many parts of the world.
What causes El Niño?
El Niño begins when the normal trade winds weaken.
When these winds become weaker, they are no longer able to push as much warm water towards the western Pacific.
Warm water then spreads eastwards.
As the eastern Pacific becomes warmer, rainfall patterns also begin to move.
These changes can weaken the winds even further.
This creates a cycle where the ocean affects the atmosphere and the atmosphere affects the ocean.
This process can continue until a strong El Niño develops.
What is La Niña?
La Niña is the opposite of El Niño.
During La Niña, the trade winds become stronger.
More warm water is pushed towards the western Pacific, while colder water becomes stronger in the central and eastern Pacific.
La Niña can also affect rainfall and temperatures around the world.
Between El Niño and La Niña, there is a normal period called ENSO-neutral.
El Niño and La Niña do not happen at fixed times. They usually occur every two to seven years.
Why does El Niño affect the whole world?
The Pacific Ocean is very large and plays an important role in controlling global weather.
When the Pacific Ocean becomes warmer in unusual areas, this changes where warm air rises and where rain falls.
These changes affect large wind systems in the atmosphere.
The effects can then spread to other parts of the world.
This is why a change in the Pacific Ocean can affect rainfall in Africa, drought in Asia or storms in the Americas.
However, El Niño does not mean that the same thing will happen everywhere.
It only increases the chance of certain weather conditions.
For example, it may increase the chance of heavy rainfall in one region and drought in another.
Why is the 2026 El Niño important?
The 2026 El Niño is expected to become very strong.
Scientists have reported very high ocean temperatures in parts of the Pacific.
Forecasts also suggest that the event may continue into early 2027.
This makes it important for governments and communities to prepare early.
A strong El Niño can increase the risk of floods, droughts, extreme heat, crop damage and other climate-related problems.
Does El Niño cause global warming?
No.
El Niño and global warming are not the same thing.
El Niño is a natural climate event that happens for several months.
Global warming is the long-term increase in the Earth's temperature caused mainly by greenhouse gases produced by human activities.
However, El Niño can temporarily make global temperatures even warmer.
This happens because heat stored in the ocean is released into the atmosphere.
Therefore, a strong El Niño happening in an already warmer world can lead to very high temperatures.
Is climate change making El Niño worse?
Scientists are still studying this question.
There is no clear evidence that climate change causes El Niño itself.
However, climate change can make the effects of El Niño more serious.
A warmer atmosphere can hold more moisture, which can lead to heavier rainfall.
Higher temperatures can also make droughts, heatwaves and wildfires more dangerous.
This means that even if El Niño remains a natural event, its impacts can become more damaging in a warmer climate.
What effects can El Niño have?
The effects of El Niño depend on the region.
Some areas may receive more rainfall than usual.
Other areas may receive less rainfall.
Heavy rainfall can cause floods, landslides and damage to roads, houses and farms.
Drought can reduce water supplies and damage crops.
Very dry conditions can also increase the risk of wildfires.
El Niño can also affect fishing, food production, health and the economy.
What can El Niño mean for East Africa?
El Niño can increase rainfall in some parts of East Africa, especially during the October to December rainy season.
Countries such as Rwanda, Uganda, Kenya, Burundi, Tanzania and Somalia may receive more rainfall than normal during some El Niño events.
More rain can be useful for farming, water supply and hydropower.
However, too much rain can also cause serious problems.
Flooding can damage houses, roads and crops.
Heavy rainfall can also increase the risk of landslides, especially in areas with steep hills.
For Rwanda, this is important because some parts of the country are highly vulnerable to floods and landslides.
How can El Niño affect agriculture?
El Niño can have both positive and negative effects on farming.
In areas where rainfall increases, farmers may benefit from more water.
However, too much rain can damage crops, increase soil erosion and cause plant diseases.
In places where El Niño causes drought, crops may fail because of lack of water.
Farmers may also lose livestock if pasture and water become limited.
This is why farmers need good weather information.
They may need to change planting dates, choose different crops or improve drainage depending on the forecast.
Can scientists predict El Niño?
Yes, scientists can often predict El Niño several months before it becomes strong.
They use satellites, ocean buoys, computer models and weather stations.
They monitor ocean temperatures, winds, rainfall and other climate conditions.
These forecasts are very important because they give governments and communities time to prepare.
However, scientists cannot always predict exactly how strong El Niño will become or exactly what will happen in every country.
Can El Niño be stopped?
No reliable method currently exists to stop El Niño.
El Niño is a very large natural climate process involving the ocean and the atmosphere.
Changing such a large system would be extremely difficult and could create other unexpected problems.
Some scientists have studied whether climate engineering could influence ocean temperatures.
However, these ideas are still experimental and could be risky.
For now, the best solution is not to try to stop El Niño.
The best approach is to prepare for its effects.
How can we reduce the risks?
Governments and communities can reduce the damage caused by El Niño through early preparation.
Weather forecasts should be shared clearly with the public.
Drainage systems should be cleaned before heavy rains.
People living in flood-prone areas should receive early warnings.
Roads, bridges, schools and hospitals should be checked for possible risks.
Farmers should be advised about suitable crops, planting times and soil protection.
Emergency teams should also prepare for floods, droughts, landslides and disease outbreaks.
Good planning can save lives and reduce economic losses.
El Niño and health
El Niño can also affect health.
Flooding can contaminate drinking water and increase the risk of diseases.
Standing water can increase mosquito breeding.
Very hot weather can cause heat-related illnesses.
Drought can reduce food production and increase the risk of hunger and malnutrition.
Heavy rainfall can also damage roads and make it difficult for people to reach health centres.
Health systems therefore need to prepare before severe weather begins.
El Niño and food security
El Niño can affect food production in many parts of the world.
If drought damages crops in one country and floods damage crops in another, global food supplies can be affected.
This can lead to higher food prices.
Countries that depend heavily on imported food may also be affected, even if they do not experience serious El Niño weather directly.
El Niño and fishing
El Niño can also affect fishing.
During normal conditions, cold water rises near the coast of South America.
This cold water contains nutrients that support fish and other marine life.
During El Niño, the water becomes warmer and the amount of cold, nutrient-rich water coming to the surface decreases.
This can reduce the number of fish in some areas.
Fishing communities can therefore lose income.
What is the main lesson?
El Niño is a natural climate event, but its effects can be serious.
The 2026 event is important because scientists expect it to become very strong.
It may increase the risk of floods, droughts, extreme heat, crop losses and health problems in different parts of the world.
However, countries today have one important advantage.
Scientists can now predict El Niño months in advance.
This gives governments, farmers, health workers and communities time to prepare.
The main challenge is therefore not only understanding El Niño.
The main challenge is using forecasts early enough to protect people, crops, infrastructure and economies.
El Niño cannot easily be stopped, but its damage can be reduced through good planning, early warning and climate preparedness.