Surface temperatures have reached a record high of 21 degrees this year – but they are set to rise higher.
The European Union released figures today indicating that ocean surface temperatures were recorded at just under 21 degrees – breaking a record which was set in March 2016.
It's believed the record will continue to be broken as ocean temperatures typically increase later in the year, according to the Copernicus climate modelling service.
This may be linked to the El Nino weather phenomenon – as the record was last broken when it occurred in 2016.
The fastest warming areas are understood to be parts of the Arctic Ocean, Baltic, and Black Sea as well as bits of the Pacific.
There was a marine heatwave off the coast of Ireland earlier in the summer. Off the coast of Florida, surface temperatures reached 38 degrees Celsius – which is around the temperature of an average hot tub.
Additional reporting from Faye Curran