Story | 25 August 2026
Global ocean hits highest temperature on record as El Niño grows
The average surface temperature of the planet’s seas outside the polar regions hit 21.1C (70F) on Saturday, according to figures from the European Copernicus climate change service
“This is unprecedented.”
PML’s Director of Science Professor Tim Smyth speaks to BBC News about the global ocean hitting its highest temperatures on record as El Niño grows, and the almost continuous marine heatwave conditions we have observed in the western English Channel – for over three years running.
Closer to Plymouth, PML’s Dr Robert Wilson shared the below graph showing record sea surface temperatures this month in the English Channel.
Dr Wilson said:
“Some may see that and think, well, a few degrees doesn’t sound like much. For everyday people, that increase doesn’t sound that dramatic until you think about your own body. A temperature rise of just a couple of degrees is enough to cause a fever, because our bodies are adapted to operate within a very narrow range.”
“Just like us – much of marine life can only exist within a specific temperature range, and these record temperatures have the potential to push species beyond their limits.”
See also:
A ‘super’ El Niño has the power to devastate fishing – and leave seals and sea lions starving
Record-breaking marine heatwave highlights the importance of long-term monitoring
What is AMOC? And what is the North Atlantic ‘cold blob’? PML’s Dr de Mora breaks down the science
