Ocean Heat Records Broken as Hottest-Ever July Temperatures Recorded

The world's oceans reached their hottest ever recorded temperatures in July 2026, according to the European Union's Copernicus Climate Change Service (C3S). The average sea surface temperature (SST) outside polar regions — between 60 degrees north and south — stood at 20.96C, surpassing the previous July record of 20.89C set in 2023.

El Nino Amplifies Human-Driven Warming

Scientists attributed the record to a combination of developing El Nino conditions in the Pacific and long-term human-driven global warming. El Nino is a natural climate cycle that warms surface waters in the central and eastern Pacific, but when layered on top of accelerating greenhouse gas emissions it can produce especially intense temperature spikes. Copernicus noted that July 2026 was also the joint second-warmest July on record globally, with air temperatures 1.47C above the pre-industrial average.

Implications for Weather and Ecosystems

Warmer oceans drive more intense hurricanes and typhoons, fuel heavier rainfall events and accelerate coral bleaching. Researchers warn that persistent above-normal SSTs reduce the ocean's ability to absorb carbon dioxide, potentially creating a feedback loop that further accelerates warming.

The record follows months of unusual heat in the Atlantic and Indian Oceans. European scientists previously documented the Rhine river falling to record low levels due to prolonged drought, another symptom of a warming climate. The findings add fresh urgency to international climate talks ahead of COP31, due to be held in 2026.