Global oceans set new June temperature record amid El Niño and climate warming
Average sea surface temperature reached 69.5°F on June 21, surpassing the previous June high, driven by El Niño and ongoing human-induced warming, prompting concerns about future weather extremes.
Average global sea surface temperature hit 69.5 °F (20.86 °C) on June 21, according to the Copernicus Climate Change Service, breaking the previous June record set in 2024. A separate Copernicus Marine Service dataset reported a temperature of 69.38 °F (21 °C) for the same day, also exceeding the prior high.
Scientists attribute the spike to the early phase of an El Niño event, which is expected to intensify, and to the long-term accumulation of excess heat in the oceans caused by human greenhouse-gas emissions. The oceans absorb about 90 % of this excess heat, acting as the planet’s primary heat sink.
"Rising sea surface temperatures are therefore not unexpected," said Michael Meredith, an ocean scientist at the British Antarctic Survey. "But the pace of warming we are now seeing is alarming."
"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. "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."
Warmer oceans can raise atmospheric temperatures, strengthen storms, and increase evaporation, which may lead to more frequent heat waves, intense rainfall, and flooding worldwide.
