Ocean temperatures reach historic highs amid rising marine heatwaves

Global ocean surface temperatures reached a historic peak in July 2026. According to data from the Copernicus Climate Change Service and the World Meteorological Organization, July tied with 2024 as the second warmest July on record, with average temperatures 1.47 °C above pre-industrial levels.

Approximately 82% of the world's oceans experienced marine heatwave conditions during the first half of the year. Exceptionally high temperatures were noted in the tropical Pacific, while the Atlantic near Europe and the western Mediterranean recorded strong to severe marine heatwaves. Experts attribute these extremes to a combination of long-term climate change and persistent meteorological patterns, such as atmospheric pressure systems that remain blocked for extended periods.

In response to rising temperatures and the resulting threat of coral bleaching, scientists at the Hawaiʻi Institute of Marine Biology and the University of Hawaiʻi are pursuing assisted evolution strategies. Researchers are identifying coral colonies that naturally exhibit higher thermal tolerance to heat stress. By using selective breeding and other conservation techniques, they aim to accelerate natural adaptation processes to help coral populations survive in increasingly warm waters.