The ocean continues to warm, and the situation is becoming increasingly concerning. The European Union’s space observation program, Copernicus, reported that sea surface temperatures reached record highs in June 2026 compared to the same period in 2023 and 2024.
On June 21, daily sea surface temperature records from the Copernicus Climate Change Service (C3S) exceeded the levels of the previous two years, reaching 20.86°C—slightly above the 20.83°C recorded in 2023 and 2024.
The Copernicus Marine Service—another entity within the program—added that these conditions were predictable given the current characteristics of the El Niño phenomenon in the equatorial Pacific.
“Current conditions could signal the start of a new phase that will take us, once again, into uncharted territory,” said Carlo Buontempo, director of C3S, adding: “With ocean temperatures at these levels and El Niño on the horizon, we are likely to see more temperature records broken in the coming months.”
According to the expert, the fact that data from both entities within the program reach the same conclusion using independent methods “highlights the strength of European science.”
Over the past three years, global ocean temperatures have been between 0.35°C and 0.73°C higher than the historical average, with increases typically occurring mainly during the northern summer.
Scientists continue to monitor the situation to determine whether this increase is temporary or persistent. Given the onset of a strong El Niño event, global temperatures are expected to reach new records in the coming months, both in the ocean and in the surface atmosphere.
The impacts of a warmer ocean
Nearly 90% of the heat from greenhouse gases is absorbed by the oceans. As a result, ocean warming is one of the clearest signs of climate change and a growing threat to marine ecosystems, coastal communities, and the planet’s climate balance.
A warm ocean causes atmospheric temperatures to remain warm for longer, intensifies storms, and increases the risk of flooding and extreme precipitation due to evaporation.
Higher sea temperatures are also associated with more frequent and intense marine heatwaves, as well as periods of unusually high ocean temperatures that disrupt ecosystems and fisheries, affect coastal economies, and can intensify episodes of extreme heat in nearby land areas.
The ocean layers extending to a depth of about 2,000 meters are home to marine life that is threatened by the effects of heat.
Ocean warming is responsible for 30 to 40 percent of current average sea-level rise. Why? When water warms, it expands.
Warmer water contains less oxygen, which leads to a loss of oxygen in the ocean and thereby compromises the ocean’s ability to sustain life and regulate the climate.
