According to the European Union (EU) Copernicus Marine Surveillance Agency, the average global ocean surface temperature in June reached 20.98 degrees Celsius, exceeding the records set in 2023 and 2024.
This record caused the ocean temperature in the first 6 months of 2026 to be at an almost unprecedentedly high level, accompanied by prolonged heat waves at sea. The average sea surface temperature in the first half of the year reached 20.04 degrees Celsius, only slightly lower than the record high of the same period in 2024.
Scientists say that the formation of a strong El Nino may continue to cause the temperature of the ocean and global atmosphere to rise in the second half of 2026 and continue to 2027.
Current conditions may signal the beginning of a new phase, once again bringing us to unprecedented levels. With ocean temperatures at the current level and El Nino approaching, it is likely that more temperature records will be broken in the coming months" - Mr. Carlo Buontempo, Director of the Copernicus Climate Change Agency, said.
Temperatures on land and in the ocean once reached an all-time high in 2024, when the El Nino phenomenon last year ended.
Mr. Simon Van Gennip, head of the Oceanographic expert group of Copernicus Marine Surveillance, emphasized that with the appearance of El Nino, "we forecast 2026 will be among the hottest years". According to him, the cause is not only from El Nino but also from warming due to greenhouse gases.
The report by the Copernicus Marine Surveillance Agency, released after a major UN scientific assessment last month, warned that the oceans around the world are falling into an "increasingly serious crisis", as seawater is heating up and rising faster.
Sea surface temperatures in the world vary from region to region in the first half of the year. The Mediterranean recorded the hottest June ever with an average temperature of 24.3 degrees Celsius, surpassing records set in 2023 and 2025. In the first 6 months of the year, 98% of the Mediterranean area was affected by sea heat waves. A sea heat wave in the northwest Mediterranean region on June 30 reached record high intensity, after a week of Europe continuously witnessing temperature records broken.
Meanwhile, the tropical Pacific region also experienced the hottest June in history with an average sea surface temperature of 27.26 degrees Celsius. Overall, from January to June, this region was equal to the record level of 2016, with the strongest and most prolonged heat rise in the western equatorial Pacific region as well as off the coast of Peru and California (USA).
