The world's oceans recorded their highest temperature for the month of June, with the global average sea surface temperature reaching 20.98°C. Data published by the European Union's Copernicus services surpass previous records from 2023 and 2024.
On June 21, a daily peak of 21.0°C was also registered — approximately 0.1°C above the values from previous record-breaking years. At the same time, the tropical part of the Pacific Ocean reached 27.26°C, which also represents the highest measured value for this period.
According to the Copernicus Marine Service, this is the culmination of a six-month period of "persistently elevated sea surface temperatures and widespread marine heatwaves" across most of the oceans. They emphasize that the levels in 2026 are "unprecedented in the entire history of satellite observations."
Experts attribute the record warming to a combination of human influence on the climate and the onset of the El Niño climate phenomenon, which leads to warming in the tropical parts of the Pacific Ocean and influences weather on a global scale. The World Meteorological Organization confirmed on June 2 that El Niño conditions are already present, warning that this will lead to above-normal temperatures "almost everywhere" and more frequent extreme weather events.
Forecasts indicate a high probability that the phenomenon will persist and intensify. According to the World Meteorological Organization, the chance of El Niño in the June–August 2026 period is about 80%, and by November it reaches 90%. Some scientists suggest that the current development could turn out to be one of the strongest in history. Professor Paul Roundy from the University at Albany commented that there is "about a 50% chance that this event will be the most powerful recorded to date."
Specialists warn that the combination of El Niño and ongoing global warming could lead to even higher temperatures in the coming months — in a zone that scientists describe as "uncharted territory." Consequences include accelerated sea level rise, intensification of extreme weather events on land, and serious pressure on marine ecosystems.
Additional data from NOAA show that a marine heatwave off the west coast of the US, which began last summer, has already raised coastal water temperatures by 3–4 degrees Fahrenheit above normal values — even before the full development of El Niño.