New Delhi: The daily global average sea surface temperature hit a new record recently, reported the Copernicus Climate Change Service. Average sea surface temperature rose to 21.1 degrees Celsius on 22 August, exceeding the earlier record of 21.09 degrees Celsius set in March 2024.
What makes such a record unusual is that global ocean temperatures usually peak around March and April, since most of the world’s ocean area lies in the Southern Hemisphere, which experiences summer at the time. However, this record was made in late August. A series of monthly readings throughout 2026 suggest that it is not an isolated warm day.
It is hardly news that climate change is making the world’s oceans warmer, and the El Niño adds more heat to an already warm ocean. According to the World Meteorological Organisation (WMO) the El Niño, developing in the Pacific ocean, is expected to grow stronger in the coming months.
“This record is another clear signal of an ocean under growing stress. El Niño is adding heat to the system, but it is doing so on top of decades of human-driven warming. As ocean temperatures continue to rise, the risks to marine ecosystems and coastal communities also increase,” said Samantha Burgess, a researcher at the European Centre for Medium-Range Weather Forecasts (ECMWF).
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A warmer ocean
The findings came out of surveys that measure the temperature of the ocean at a depth of 10 metres. But the consequences of such temperature rise go far deeper.
According to Burgess, many of these consequences are already visible. The number of marine heatwave days globally has more than tripled since the early 1990s, putting increasing pressure on marine ecosystems and the communities that depend on them.
Higher temperatures in the long run can affect the survival of coral reels, seagrass meadows, and disrupt marine food systems and even fisheries. Warmer oceans also transfer more heat and moisture to the atmosphere, and could lead to more intense rainfall and storms. When temperatures rise, the ocean is also less efficient at absorbing carbon dioxide from the atmosphere.
Scientists from the ECMFW in collaboration with the Copernicus Climate Change Service (C3S) will keep monitoring the rise in temperatures to see whether this sudden peak in sea surface temperature is temporary.