Scientists warn 2027 could be the hottest year on record

Scientists are warning of a possible ‘Super El Niño’ developing in the summer of 2026, which could push 2027 toward becoming the hottest year on record.

The World Meteorological Organization (WMO) says an El Niño event could develop from mid-year, with Daniel Swain of the California Institute for Water Resources warning that this could drive record-high temperatures in 2026 and 2027.

Meteorologist and climate specialist Jeff Berardelli told US broadcaster WFLA-TV: "I believe we will experience weather events unlike anything we've seen in modern history."

Every two to seven years, sea surface temperatures in the eastern tropical Pacific Ocean rise in a phenomenon known as El Niño.

Professor Francois Engelbrecht, a climatologist at the Global Change Institute at the University of the Witwatersrand, explained the mechanics to News24.

“The warming of the Pacific Ocean over tens of thousands of square kilometres disrupts atmospheric circulation patterns across the entire globe,” he said.

"Large upward air currents develop over the ocean, triggering a chain reaction across the southern hemisphere. These often result in multiple high-pressure systems forming over southern Africa during the summer months."

“And high-pressure systems are very unfavourable for precipitation; they cause the air to sink, and with this widespread sinking, clouds cannot form, so it cannot rain,” Engelbrecht told News24.

“That is why El Niño events are associated with the worst droughts we have ever experienced in South African history.”

When average sea surface temperatures in the eastern tropical Pacific exceed 2°C above normal, the event is classified as a Super El Niño.

"If El Niño does indeed occur in the summer of 2026, which we see as highly likely, we don’t know for sure whether it will be a Super' El Niño, but we assume there is a very high probability that 2027 will be the warmest year on record,” Engelbrecht added.

How likely?

Sea surface temperatures in parts of the tropical Pacific have warmed more than usual in recent months, a typical precursor to El Niño, according to the science journal Nature. Whether winds and other atmospheric factors will intensify or weaken this warming, and thus determine the strength of any El Niño, remains uncertain.

The US National Oceanic and Atmospheric Administration (NOAA), in a forecast released last Thursday, put the probability of an El Niño developing between May and July at 82%, with a 96% chance of it persisting through December.

However, NOAA estimated only a 37% probability that it would reach the "very strong" classification, in which sea surface temperatures exceed 2°C above average across the central and eastern tropical Pacific.

The European Centre for Medium-Range Weather Forecasts estimated in May that sea surface temperatures could reach 3°C above average by November.

The outlook is expected to become clearer over the northern hemisphere summer, as El Niños typically peak between October and February.

The last El Niño, in 2023–24, brought drought and famine to parts of southern Africa and record flooding in southern Brazil, and contributed to 2024 becoming the hottest year on record. The most recent Super El Niño, in 2015–16, was severe enough that Botswana lost 40% of its cattle to drought.