Global ocean surface temperatures stayed at record highs for 100 straight days from June 2 to September 10, 2026, according to University of Maine Climate Reanalyzer data. The average sea surface temperature hit 21.18°C in late August. Scientists attribute the heat to climate change, with an intensifying El Niño adding extra warming. The article notes that the ocean absorbed 23 zettajoules of heat in 2025, a 43% jump from the previous year. That heat is already showing up in marine ecosystem shifts, coastal heatwaves, and higher wet bulb temperatures that make it harder for people to cool down. UNEP now expects global temperatures to blow past the 1.5°C Paris target within a few years. For anyone tracking climate risk, this story is a useful update on physical indicators and why emissions cuts keep getting urgent. It also points to the need for adaptation in coastal communities, fisheries, and power grids.
