The European Union’s Copernicus Marine Service reported that the global average sea surface temperature reached approximately 21.0 degrees Celsius in June, breaking previous records set in 2023 and 2024.
The Earth’s oceans have just recorded their hottest June ever, and new highs could be reached in the coming months due to El Niño and climate change increasing temperatures even more.
The global average sea surface temperatures in June were 20.98C, surpassing the records of 2023 and 2024 pic.twitter.com/dSfGdjHxPf
— AFP News Agency (@AFP) July 1, 2026
Marine heatwaves are spreading worldwide
The EU’s marine environment monitor indicated that the first half of 2026 was characterized by unusually high ocean temperatures and extensive marine heatwaves. By the end of June, roughly 82% of the world’s oceans had experienced marine heatwaves.
“Marine heatwaves progressed steadily during this timeframe, ultimately impacting around 82 percent of the global ocean,” quoted Simon van Gennip, lead oceanographer for the Copernicus Marine Service, in Al Jazeera.
Regions such as the Mediterranean Sea, central North Atlantic, and equatorial Pacific reported notably high temperatures, revealing that the oceans are experiencing ongoing heat stress.
El Niño may elevate temperatures further
Researchers noted that the potential resurgence of El Niño later this year could further boost temperatures in both ocean and atmospheric conditions. Carlo Buontempo, Director of the Copernicus Climate Change Service, mentioned that current conditions could indicate the onset of “a new phase, leading us once again into uncharted territory.”
“With ocean temperatures at these levels and El Niño approaching, we are likely to witness even more temperature records being broken in the upcoming months. The consistency of findings from Copernicus Marine data through various methods underscores the strength of European science — highlighting the critical importance of open, reliable data,” Buontempo emphasized.
The significance of warmer oceans
This report arrives shortly after a major UN scientific assessment warned of a ‘deepening crisis’ within the world’s oceans as they continue to warm and sea levels rise. Oceans absorb about 90% of the excess heat created by greenhouse gas emissions, playing a crucial role in regulating the Earth’s climate. However, elevated ocean temperatures also increase atmospheric moisture, intensifying heavy rainfall and tropical cyclones.
Furthermore, warmer seas contribute to rising sea levels and impose extra strain on marine ecosystems, including coral reefs, which may bleach and perish during extended marine heatwaves.
Understanding El Niño
El Niño is a climatic phenomenon prompted by unusually warm waters in the tropical Pacific. The World Meteorological Organization (WMO) indicates that these conditions are developing and are expected to affect global temperatures and precipitation, heightening the risk of extreme weather in the coming months.
