October 2026 was the hottest October on record globally, with temperatures 1.75°C above pre-industrial levels, according to Copernicus.
Global temperatures exceeded the 1.5°C threshold for the third consecutive month, while 2026 is on course to become the second-warmest year on record.
An exceptionally strong El Niño pushed ocean temperatures to record highs, with the Niño 3.4 region recording an unprecedented 3.21°C anomaly.
The four-year global temperature average for 2023–2026 is also expected to exceed 1.5°C above pre-industrial levels.
October 2026 was the warmest October on record globally, with 2026 on course to exceed 1.5 degrees Celsius (°C) above the pre-industrial average (1850-1900), according to the latest update from the Copernicus Climate Change Service (C3S), implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF). If this happens, 2026 would become the second year after 2024 to breach the 1.5°C threshold.
The global average surface air temperature in October was 15.35°C, which was 0.9°C above the 1991-2020 average and 1.75°C above the pre-industrial average, according to C3S. October was the third consecutive month, after August and September, to exceed 1.5°C above the pre-industrial average. The last time three consecutive months breached this threshold was between February and April 2025.
Based on temperature data recorded up to October, C3S estimated that the annual global average temperature in 2026 would likely be between 1.56°C and 1.61°C above pre-industrial levels. There is an 80 per cent probability that 2026 will become the second-warmest year on record and a 20 per cent chance that it could equal or surpass 2024 as the warmest year on record.
“The four-year average global temperature for 2023-2026 is also expected to exceed 1.5°C above pre-industrial levels,” according to a press release from C3S.
The average sea surface temperature (SST) in oceans outside the polar regions reached 20.95°C in October 2026, the highest on record for the month, surpassing the previous record set in October 2023. The SST anomaly in the Niño 3.4 region, which is used to measure the strength of the ongoing, exceptionally strong El Niño event, also broke records.
“In October, the monthly average SST in the Niño 3.4 region reached an all-time high of 29.94°C, with a record anomaly of 3.21°C. Both values exceeded those reached during the peaks of the previous very strong El Niño events of 1982-1983, 1997-1998 and 2015-2016, highlighting the exceptional intensity of the current El Niño”, according to the C3S press statement.
Many parts of the world experienced drier-than-average conditions in October 2026. These included eastern North America, the southern United States, parts of western and central-eastern Europe, western Russia, Siberia, Central Asia, southern China, South America and southern Africa.
Other regions such as “Alaska, part of the southern USA and northern Mexico, a large region of central Asia, parts of China and Korea, Chile, southern Argentina and southeastern Brazil, as well as southernmost Africa, Madagascar, and western and central Australia” experienced wetter than average conditions in October 2026.
“October has continued the pattern of remarkable global warmth, with record global and surface ocean temperatures. An exceptionally strong El Niño is adding further heat to a climate already warmed by human activities, while 2026 is on track to become the second calendar year above 1.5°C,” noted Samantha Burgess, strategic lead for climate at ECMWF.
“Particularly significant is that the four-year average is also expected to exceed 1.5°C, highlighting how sustained this period of global warmth has become,” Burgess added.