Last month was the warmest October the planet has ever recorded, and Europe’s Copernicus Climate Change Service now puts the odds that 2026 ends more than 1.5C above pre-industrial levels at better than 99 percent. That would make it only the second calendar year, after 2024, to cross that line.
Global surface air averaged 15.35C in October, according to the agency’s ERA5 data. That is 1.75C warmer than the 1850-1900 baseline and 0.90C above the 1991-2020 norm for the month. That makes August, September and October a run of three months beyond the 1.5C level.
For the year as a whole, the statistical forecast points to an anomaly of between 1.56C and 1.61C. There is roughly an 80 percent chance that 2026 finishes as the second-hottest year, and about one chance in five that it matches or beats 2024’s record. Averaged across 2023 through 2026, the four years together should likewise land beyond that level.
The oceans are doing much of the heavy lifting. Sea surface temperatures outside the polar regions hit 20.95C, an October record, while El Niño keeps strengthening in the tropical Pacific. In the Niño 3.4 zone, the temperature anomaly reached 3.21C, the highest value Copernicus has ever measured there.
Europe saw its second-warmest October, with Scandinavia and the east of the continent unusually mild. Big rivers such as the Rhine, Danube and Vistula stayed very low, even as Britain, Ireland, Spain, Greece and Turkey dealt with heavy rain and floods.
One caveat matters: the Paris Agreement goal refers to warming averaged over the long term, typically around twenty years, so a single hot year does not mean the target has formally been missed. Scientists nonetheless warn that every year spent above the line brings more severe heatwaves, droughts and floods, and that such years will become more frequent as the climate keeps warming.
