October 2026 was the warmest October on record globally, the European Union's Copernicus Climate Change Service said on Friday, November 6, 2026 — and the year is now virtually certain to finish above 1.5 degrees Celsius, a threshold the world has crossed only once before. It is the latest sign the planet's long hot spell is not letting up.

The month averaged 15.35 degrees Celsius worldwide, 0.90 degrees above the 1991-2020 average and 1.75 degrees above the 1850-1900 pre-industrial level. It was the third month in a row above 1.5 degrees, after August and September, as a powerful El Niño gathers strength in the tropical Pacific.

Key Points

• October 2026 was the warmest October on record, averaging 15.35°C globally — 1.75°C above the pre-industrial level, Copernicus said on November 6, 2026.
• It was the third consecutive month above 1.5°C, after August and September, as El Niño conditions intensify in the tropical Pacific.
• 2026 is now virtually certain — over 99% probability — to exceed 1.5°C for the full year, with a predicted range of 1.56°C to 1.61°C, becoming only the second calendar year to do so after 2024.
• 2026 is most likely to be the second-warmest year on record, with about a 20% chance of tying or beating 2024, currently the warmest year on record.
• Ocean temperatures outside the polar regions hit 20.95°C in October, the highest ever recorded for the month, beating the previous October record set in 2023.

What Happened

The Copernicus Climate Change Service, run by the European Centre for Medium-Range Weather Forecasts, published its monthly bulletin on Friday, November 6, 2026, confirming October as the warmest October in its ERA5 dataset, which stretches back to 1940. The bulletin, based on data through the end of October, also carried the year's biggest call yet: 2026 is virtually certain to finish above 1.5 degrees Celsius for the full calendar year. Only 2024 has done that before. The four-year average temperature for 2023 to 2026 is also expected to exceed 1.5 degrees, Copernicus said, underlining how sustained the current warmth has become rather than a single hot year standing alone.

Background: How the Planet's Fever Is Measured

Copernicus tracks global temperature with ERA5, a reanalysis that blends billions of observations from satellites, ships, aircraft and weather stations into a single consistent picture of the atmosphere. Its pre-industrial baseline is 1850-1900, the period scientists use to judge warming since the industrial era began. The Paris Agreement's 1.5-degree goal refers to a long-term average over decades, so a single calendar year above it does not count as a formal breach — but each year that crosses the line brings the long-term average closer to it. The last run of at least three consecutive months above 1.5 degrees ended in April 2025, making this the first such run in more than a year.

Warmest October on Record: The Numbers Behind the Heat

The heat was not confined to one region. Europe had its second-warmest October on record, averaging 11.51 degrees Celsius over land, 1.49 degrees above the 1991-2020 average, behind only 2022. The oceans told an even sharper story: sea surface temperatures outside the polar regions averaged 20.95 degrees, the highest October figure on record, and in the Niño 3.4 region of the tropical Pacific the monthly anomaly reached a record 3.21 degrees, beating the peaks of the very strong El Niño events of 1982-83, 1997-98 and 2015-16. Dry conditions gripped much of central and eastern Europe, with exceptionally low flows on the Rhine, Danube and Vistula, while heavy rain and flooding hit the UK and Ireland, Spain, Greece and Türkiye.

Reactions and Quotes

Samantha Burgess, strategic lead for climate at ECMWF, said the month fits a pattern that is now hard to miss. "October has continued the pattern of remarkable global warmth, with record global and surface ocean temperatures," she said. "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. 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." El Niño alone does not explain the records: it arrives on top of decades of human-caused heating.

Why It Matters

A second calendar year above 1.5 degrees, coming just two years after the first, changes the conversation about the Paris goal. The target was written as a long-term average, but scientists watch annual crossings as a warning that the long-term line is approaching fast — the world is now on course for a four-year average above 1.5 degrees for 2023 to 2026. The heat also has immediate costs: warmer oceans fuel stronger storms and heavier rain, dry rivers strain water supplies and shipping, and heatwaves put health systems under pressure, as recent record heat deaths show. The bulletin lands three days before the COP31 climate talks open in Antalya, Turkey, on November 9, giving negotiators fresh evidence of the gap between pledges and temperatures.

What Happens Next

El Niño is expected to peak toward the end of the year, which could push November and December temperatures higher still and help decide whether 2026 merely finishes second-warmest or challenges 2024 for the top spot — Copernicus gives it about a 20% chance of tying or beating 2024. The final annual ranking will be confirmed in January, when the full year's data are in. In the meantime, the COP31 talks in Antalya will test whether governments respond to the new numbers with stronger emissions cuts and more money for the countries hit hardest. Other datasets may differ slightly, but the direction is clear.

Frequently Asked Questions

How warm was October 2026?
October 2026 averaged 15.35°C globally, the warmest October on record — 0.90°C above the 1991-2020 average and 1.75°C above the 1850-1900 pre-industrial level.

Is 2026 certain to exceed 1.5°C for the year?
Copernicus says it is virtually certain, meaning more than 99% probability, with a predicted range of 1.56°C to 1.61°C above pre-industrial levels. It would be only the second calendar year to do so, after 2024.

Does one year above 1.5°C break the Paris Agreement?
No. The Paris target refers to a long-term average over decades, so a single year above 1.5°C does not count as a breach — but annual crossings bring the long-term average closer to the limit.

What role is El Niño playing?
El Niño conditions in the tropical Pacific are intensifying and expected to peak late in the year. The Niño 3.4 region set a record anomaly of 3.21°C in October, adding heat to long-term human-caused warming.

How likely is 2026 to be the warmest year ever?
Most likely it will be the second-warmest year on record, with about an 80% probability, and about a 20% chance of tying or exceeding 2024, currently the warmest year on record.

Related coverage: Paris Agreement at 10: World Blows Past 1.5C as UNEP Says Limit Is Lost, Guterres Calls COP31 Climate Talks a 'Moment of Truth' in Final Plea as UN Chief, and Lancet Warns Heat Deaths Hit Record 710,000 as Climate Emergency Call Grows Ahead of COP31.