Oceans reach hottest June on record as El Niño threatens higher temperatures The world's oceans recorded their hottest June ever, European scientists said on Wednesday, warning that the emergence of an El Niño weather pattern alongside human-driven climate change could push sea and air temperatures to fresh records in the months ahead. The world's oceans experienced their hottest June on record and could reach new highs in the coming months as El Niño and human-driven climate change push temperatures even higher, scientists said on Wednesday. Global average sea surface temperatures in June were 20.98C, beating the previous records of 2023 and 2024, according to the European Union's Copernicus Marine Service.

The record capped six months of near-unprecedented ocean warmth in 2026, with prolonged marine heatwaves, the service said. Average sea temperatures in the first half of the year were 20.04C, slightly below the high set in the same period in 2024. Scientists said the onset of a potentially powerful El Niño weather pattern could boost global heat in the oceans and atmosphere even further in 2026 and into next year.

"Current conditions could indicate the beginning of a new phase, leading, once more, to uncharted territory," said Carlo Buontempo, director of the Copernicus Climate Change Service, the EU's climate monitor. "With ocean temperatures at these levels and El Niño on the horizon, we are likely to see more temperature records fall in the coming months," Buontempo said in a statement. Read more‘Fuel on the fire’: Scientists confirm El Nino’s return, predict extreme weather effects El Niño is marked by unusually warm waters in parts of the Pacific Ocean, releasing more heat into the atmosphere and influencing wind, cloud and weather patterns around the globe.

This can raise the risk of weather extremes ranging from floods in Peru to droughts in parts of Africa and wildfires in Australia. But it can also cause a temporary spike in global temperatures, compounding the long-term warming caused by humanity's burning of fossil fuels. Land and sea temperatures reached an all-time high in 2024 at the tail end of the last El Niño.

"With the arrival and the onset of an El Niño year... we can expect that 2026 will be amongst the warmest (ever) recorded," Simon Van Gennip, lead oceanographer for the Copernicus Marine Service, said in a news briefing. "This is due to El Niño ...

but also from the warming due to the greenhouse gas emissions we continue to provide for the atmosphere," Van Gennip said. Read moreEU refuses to take side for or against air conditioning amid record-breaking heatwave 'Deepening crisis' The report follows a warning issued in a major UN scientific assessment last month which declared that the world's oceans were in a "deepening crisis" as seas were warming and rising faster. Oceans are a key regulator of Earth's climate because they absorb some 90 per cent of the excess heat caused by humanity's release of greenhouse gases such as carbon dioxide.

Warmer oceans increase moisture in the atmosphere, providing fuel for tropical cyclones and destructive rainfall. Hotter seas also directly contribute to sea level rise – water expands when it warms up – and create unbearable conditions for tropical reefs, whose corals can bleach and die during prolonged marine heatwaves.