A super El Niño event could make 2026 the hottest year on record, a leading climate scientist has warned.

It is now almost certain that a warming El Niño cycle will begin in the second half of the year, with some models suggesting it could be the strongest of the century.

A group of scientists, led by Dr James Jansen of Columbia University, say this has a very strong chance of making 2026 the hottest ever recorded.

That could mean beating the record set in 2024, when global warming exceeded 1.5°C (2.7°F) above the pre–industrial average for the first time.

El Niño years form part of a natural cycle known as the El Niño–Southern Oscillation, and are marked by sustained warm temperatures across the Pacific Ocean.

Combined with the heating effects of human–caused climate change, the researchers predict this will make 2026 0.06°C (0.11°F) hotter than 2024.

Dr Jansen and his co–authors write in a blog post: 'That margin is wide enough that we are willing to make the prediction that 2026 will be the warmest year.

'Of course, 2027 will be still hotter.'

The El Niño–Southern Oscillation is a natural climate pattern which cycles between a hot El Niño and a cool La Niña phase every two to seven years.

During the El Niño part of the cycle, warm waters that build up in the Pacific spread out and raise the Earth's average surface temperature.

Currently, global warming is being held in check by a cooling La Niña pattern that is making 2026 a little bit less hot than previous years.

Compared to 2024, the first three months of this year have been about 0.1°C (0.18°F) cooler on average.

For this year to go on to become the hottest on record, the next seven months will need to be brutally hot.

Unfortunately, that is precisely what Dr Jansen and his colleagues believe will happen.

According to the latest report from the World Meteorological Organisation (WMO), the return of strong or 'super' El Niño conditions is likely as early as May or June.

Some scientists have even suggested that we could be approaching the strongest El Niño cycle in the last 140 years, with the potential to send global temperatures soaring.

Previous estimates suggested that 2026 might be 1.47°C (2.65°F) above the pre–industrial average, making it the second–warmest on record.

However, Dr Jansen says these predictions underestimate the impact of global warming and the coming El Niño weather.

The average sea surface temperature, which is much less affected by fluctuations in weather, is currently 0.13°C (0.23°F) warmer than it was before the start of the 2023 El Niño year.

'Given that land covers 30% of the globe, the ocean gap of 0.13°C implies a global warming of 2026 relative to 2023 of 0.17°C,' the researchers explain.

'Global temperature in 2024 was 0.11°C higher than in 2023. Thus, if 2026 ultimately exceeds 2023 by 0.17°C, it would break the 2024 global temperature record by 0.06°C.'

Dr Jansen's predictions suggest that the world will be considerably warmer in the coming months than many scientists had expected.

For example, the Met Office's annual forecast published in December last year predicted that 2026 would be 1.46°C (2.63°F) above the pre–industrial average – with a range between 1.34°C (2.41°F) and 1.58°C (2.84°F).

However, Dr Jansen and his colleagues argue that most models underestimate how sensitive the climate is to the effects of global warming.

Data suggests that small increases in greenhouse gas concentrations may produce more warming than most climate models assume.

This means the world will keep getting hotter at a faster rate than many people are prepared for.

If Dr Jansen's predictions are correct, the UK is likely heading into one of the hottest summers ever experienced.

El Niño years typically lead to hotter and drier summer conditions in Europe, Australia, Southeast Asia, and southern Africa.

While its effects on the UK are yet to be determined, meteorologists say El Niño's intensity will likely be comparable to the 1997/98 event, which saw global temperatures reach their highest on record.

During its development, the UK experienced an exceptionally hot, sunny and humid August characterised by heatwaves.

The average maximum temperature at Heathrow in August 1997 was 25.8°C (78.4°F), with a top temperature of 31.5°C (88.7°F) reached.