October 2026 was the warmest October on record, Copernicus says

October 2026 was the warmest October on record globally, according to the Copernicus Climate Change Service. Its October bulletin says the global average surface air temperature was 15.35°C, which is 0.90°C above the 1991-2020 average for the month. The previous October record was set in 2023, at 0.85°C above that average. Copernicus, which is implemented by the European Centre for Medium-Range Weather Forecasts, said the month was 1.75°C above the 1850-1900 pre-industrial average.

Third month above 1.5°C

October was the third consecutive month more than 1.5°C above pre-industrial levels. Before August 2026, the last month to exceed that level was November 2025, and the previous run of at least three consecutive months ended in April 2025. Over the 12 months from November 2025 to October 2026, the global average was 1.51°C above pre-industrial levels and 0.63°C above the 1991-2020 average.

Global land temperature in October averaged 10.82°C, the joint third highest for the month, matching October 2025 and trailing only 2023 and 2024.

Where 2026 stands

Based on January through October, 2026 ranks as the second-warmest year on record at 0.64°C above the 1991-2020 average. That is 0.07°C below the same period in 2024 and 0.05°C above 2023. A Copernicus statistical model predicts a full-year anomaly of 0.68°C to 0.73°C above the 1991-2020 average, equal to 1.56°C to 1.61°C above pre-industrial levels.

The model gives 2026 about an 80 percent probability of ending as the second-warmest year and about a 20 percent chance of tying or exceeding 2024, the warmest on record at 0.72°C above average. It puts the probability of the year exceeding 1.5°C at more than 99 percent. That would make 2026 the second calendar year to do so in the ERA5 dataset after 2024, and Copernicus said the 2023-2026 four-year average would also exceed 1.5°C.

Record ocean heat and El Niño

The average sea surface temperature across the extra-polar ocean, from 60°S to 60°N, was 20.95°C in October. That is the highest value on record for the month and the fourth consecutive month to set a record for its month. The previous October record came in 2023, when a strong El Niño was also developing, but Copernicus said the 2026 event is much stronger.

The average October sea surface temperature in the Niño 3.4 region, which scientists use to monitor El Niño, reached an all-time high of 29.94°C. That surpassed the record set in September and the peak values of the very strong El Niño events of 1982-83, 1997-98 and 2015-16. The October anomaly there was 3.21°C above the 1991-2020 average, compared with the previous record of 2.99°C in September. Across much of the central equatorial Pacific, monthly sea surface temperatures were more than 3°C above average, and the largest anomalies, 6°C to 7°C, occurred along the Peruvian coast and west of the Galápagos.

Regional patterns

West Antarctica showed the largest positive temperature anomalies in the world for the third month running, more than 7°C above average and up to 11°C above average in some areas. Copernicus linked this to high-pressure anomalies over the Drake Passage, a pattern typically associated with El Niño. Warm anomalies were also pronounced across Siberia, the central United States, northern Canada, eastern Africa and the Middle East. Southern South America, Greenland, northern Africa, pockets of central Asia and western Australia were colder than average.

Europe had its second-warmest October in the ERA5 dataset, at 11.08°C, which is 1.49°C above the 1991-2020 average and 0.43°C cooler than the record set in 2022. Ukraine had the largest anomalies on the continent, reaching 6°C above average. Southern Italy, the southern Balkans, Greece, the eastern Mediterranean and western Türkiye were up to about 2°C below average.

Copernicus cited the World Meteorological Organization as saying El Niño is strengthening rapidly and is expected to peak in December 2026, becoming one of the strongest events on record. The WMO said it is now almost certain to persist through February 2027.