Scientists using European Union monitoring say the world’s oceans reach their hottest June on record, with global average sea surface temperatures hitting 20.98°C. The figure surpasses previous record highs set in 2023 and 2024, according to the EU Copernicus Marine Service. Reports also describe sustained ocean warmth in the first half of 2026, including widespread marine heatwaves affecting large portions of the oceans. The monitoring shows that early-year average sea temperatures are near historic levels, with the first half of 2026 reported at 20.04°C. Scientists link the extreme ocean warmth to a combination of long-term human-caused climate change and the emergence of El Niño, a Pacific weather pattern associated with unusually warm sea temperatures. Multiple outlets cite warnings that El Niño could transfer more heat from the ocean to the atmosphere and raise the likelihood of additional temperature records in coming months. The reports also note that El Niño can influence global weather patterns and increase the risk of extreme events, while ocean heat contributes to sea level rise and marine ecosystem stress, including coral bleaching during prolonged heatwaves.