October was the warmest on record globally, with sea temperatures also setting records as an exceptionally strong El Niño intensifies
The European Union’s Copernicus Climate Change Service said on 6 November 2026 that the year is “virtually certain” to finish more than 1.5 degrees Celsius (notated as 1.5C or 1.5 degrees C) above preindustrial levels.
Based on data through October, it puts the probability above 99% and forecasts an annual average between 1.56 C and 1.61C. That would make 2026 the second calendar year to cross the 1.5C threshold, after 2024.
The announcement was made days before governments gather for the COP31 climate summit in Antalya, Turkey on 9 November 2026. Copernicus also reported that October was the warmest October on record worldwide. Its average global surface air temperature was 15.35 degrees C, or 1.75 degrees above the 1850–1900 preindustrial baseline. It was the third consecutive month to exceed 1.5C.
October’s previous record, 1.7C above preindustrial levels, was set in 2023. Sea surface temperatures outside polar regions had averaged 20.95 degrees C, another monthly record. “October has continued the pattern of remarkable global warmth, with record global and surface ocean temperatures,” said Samantha Burgess, strategic lead for climate at the European Centre for Medium-Range Weather Forecasts, which operates Copernicus. She said an exceptionally strong El Niño was adding heat to a climate already warmed by human activity.
A noted persistence in surface warming
Copernicus expects 2026 to be the second-warmest year on record, with about a 20% chance of matching or surpassing 2024, the current record holder. Other datasets suggest a greater chance of a new record: a Carbon Brief analysis has put the odds at up to 97% in Berkeley Earth’s data and roughly 67% across six datasets combined.
Burgess added that result shows how persistent the current period of global warming has become. The El Niño has not yet reached its peak. In September, it had set a daily record in the Niño 3.4 region, the central equatorial Pacific area used to monitor the phenomenon. Nearly all models expect it to become the strongest El Niño on record, peaking near 4C this winter. The World Meteorological Organization expects it to peak in December 2026 and persist through February 2027.
At current emission rates, that would be a level of sustained warming the planet could reach within 10 to 15 years. “Climate change is turbocharging extreme weather, and when we add an off-the-charts El Niño into the mix, we can expect some serious impacts this year and next,” said Ella Gilbert, who was the lead of a Royal Meteorological Society briefing.
