What are El Niño and La Niña? Warnings of record-breaking warm weather issued

·3-min read
The Earth is on course for its hottest year on record by 2027  (Getty Images)
The Earth is on course for its hottest year on record by 2027 (Getty Images)

Brits are set to soak up the sunshine this coming bank holiday weekend, with dry and warm weather predicted.

Some experts that the hot weather approaching Britain is partly caused by a weather phenomenon known as El Niño.

Much of the country is expected to see warm spells throughout the next couple of weeks and now, the Met Office has released a five-day weather forecast for the UK that predicts some lovely weather conditions for the last week of May.

Neil Armstong, Met Office chief forecaster, said: “If you have heard media hyperbole that a heatwave driven by an African plume will bring intense heat to the UK in the next few days you are going to be disappointed – this isn’t true.

“However, if you are looking forward to a spell of largely fine, sunny and warm conditions across the majority of the UK, then you are going to be in luck.”

No super hot heatwave is expected this weekend, but weather experts have said it won’t be long until they do arrive.

Scientists have warned that the world could breach the 1.5C climate threshold by 2027.

Research from the World Meteorological Organization (WMO) has found that it is highly likely that the world will experience record-breaking temperatures in the next five years. Scientists said that the increasing global temperatures were down to both human activity as well as the developing El Niño weather system.

The WMO’s secretary-general, Professor Petteri Taalas, said in the report: “A warming El Niño is expected to develop in the coming months and this will combine with human-induced climate change to push global temperatures into uncharted territory. This will have far-reaching repercussions for health, food security, water management and the environment. We need to be prepared.”

So what is the naturally occurring El Niño weather system and its opposing phase, La Niña?

What are the El Niño and La Niña weather events?

El Niño and La Niña refer to fluctuation in the Earth’s climate system, according to the Met Office. They mean little boy and little girl in Spanish respectively. It is believed that they got their names from South American fishermen in the 1600s, who noticed periods of unusually warm water. It was initially called El Niño de Navidad (which means Christmas in Spanish) because El Niño typically peaks around December.

During El Niño the sea surface temperature rises, usually in the central-east equatorial Pacific, and it typically occurs every few years. During this phase, the tropical eastern Pacific will experience warmer than average weather.

On the other hand, La Niña is when the sea surface temperature becomes cooler than average, with sea temperatures often dropping by 3C to 5C below average. This results in cooler than average weather in the tropical eastern Pacific.

The Earth’s climate system experiences neutral phases when the temperatures are closer to the long-term averages.

What are the impacts of El Niño and La Niña?

El Niño and La Niña affect weather around the world. For example, El Niño can increase the chance of the UK having cold winters but it also limits the development of tropical storms in the North Atlantic. These phases can last anywhere from around nine months to a few years, according to the National Oceanic and Atmospheric Administration. According to the WMO, the Earth has been in the La Niña phase for the past three years, which has “temporarily reined in the longer-term warming trend”.

However, La Niña ended in March 2023 and El Niño is forecast to develop in the coming months.

There is a 98 per cent chance of at least one of the next five years breaking temperature records, as well as a 98 per cent chance that the next five years are hotter on average than the past five years.