Ocean Temperatures Hit Record High — 2025 Sets a New Benchmark

The Copernicus Climate Change Service (C3S) confirmed that global sea-surface temperatures averaged 21.2 °C between April and September 2025, surpassing the previous 2023 record.
The NOAA reported that over 40% of global ocean surfaces experienced marine heatwaves this year, with coral bleaching risks intensifying across the Indian and Pacific Oceans.
C3S climate analysts attribute this to ongoing greenhouse gas accumulation and El Niño reinforcement cycles.