2026 Is Almost Certain to Be the Second Year Ever Above 1.5°C — and Likely the Second-Warmest on Record

BRUSSELS — The year 2026 is now virtually certain to finish more than 1.5°C above pre-industrial temperatures, the European Union's Copernicus Climate Change Service said on Friday, 6 November 2026, making it only the second calendar year on record to pass that mark after 2024. The finding, in Copernicus's October climate bulletin, follows the warmest October ever recorded — a month that averaged 15.35°C worldwide, 1.75°C above the pre-industrial level — and it lands three days before world leaders gather in Antalya, Turkey, for the COP31 climate talks. Copernicus also said 2026 is most likely to rank as the second-warmest year ever recorded, with about a 20 percent chance of tying or beating the 2024 record.

Illustration: Planet Earth wrapped in bands of record heat, after October 2026 became the warmest October ever recorded.

What Happened

Copernicus published its October 2026 climate bulletin on Friday, 6 November 2026, and the headline numbers are stark. October 2026 was the warmest October on record globally, with a global-average surface air temperature of 15.35°C, according to ERA5 data from the European Centre for Medium-Range Weather Forecasts (ECMWF), which operates Copernicus. That figure was 0.90°C above the 1991–2020 average and 1.75°C above the estimated 1850–1900 pre-industrial average.

October was the third consecutive month in which global temperatures ran more than 1.5°C above the pre-industrial level, Copernicus said. The previous run of at least three straight months above the mark ended in April 2025. The bulletin puts the predicted range for the 2026 annual global temperature at 1.56°C to 1.61°C above the pre-industrial level, which would make 2026 the second calendar year to exceed 1.5°C, after 2024.

Copernicus said 2026 is most likely to be the second-warmest year on record, with about an 80 percent probability of finishing second, according to Anadolu Agency's reporting of the bulletin. There remains about a 20 percent chance that 2026 could tie or exceed 2024, currently the warmest year on record. The four-year average from 2023 to 2026 is also expected to break the 1.5°C mark, Copernicus said — significant because the Paris goal is a long-term average, not a single year.

The oceans told the same story. In October, the average sea surface temperature outside the polar regions reached 20.95°C, the highest on record for the month, surpassing the previous October record set in 2023. In the tropical Pacific, where El Niño conditions continued to intensify, the monthly sea surface temperature anomaly in the Niño 3.4 region — the central-equatorial Pacific zone used to monitor El Niño — reached an all-time high of 3.21°C above average, exceeding the peaks of previous very strong El Niño events. The region's average sea surface temperature reached 29.94°C in October. "October has continued the pattern of remarkable global warmth, with record global and surface ocean temperatures," said Samantha Burgess, strategic lead for climate at ECMWF. "An exceptionally strong El Niño is adding further heat to a climate already warmed by human activities," she added.

Europe recorded its second-warmest October, with an average land temperature of 11.51°C, or 1.49°C above the 1991–2020 average, according to Anadolu Agency. Arctic sea ice extent was about 9 percent below average, with the Kara Sea reaching a record low for the month. Dry conditions spread across western Iberia, parts of France, central-eastern Europe, the Balkans and peninsular Italy, and river flows ran exceptionally low in the Danube, Vistula and Rhine.

Background

Copernicus draws on ERA5, a reanalysis dataset produced by ECMWF that blends observations from satellites, weather stations, ships, aircraft and buoys into a consistent picture of the atmosphere. The pre-industrial baseline is the period 1850–1900, the earliest era with enough observations to estimate an average.

The 1.5°C figure comes from the Paris Agreement, adopted in 2015, under which countries agreed to try to limit global warming to 1.5°C above pre-industrial levels. Crucially, the target refers to a long-term average, so a single year above the mark does not mean it has been breached, as Reuters noted. A second calendar year above 1.5°C shows how close the long-term average is running to the limit, and the expected four-year average for 2023–2026 above 1.5°C underlines that the overshoot is no longer a one-off event.

El Niño is the other half of the story. It is a natural warming of surface waters in the central and eastern tropical Pacific that shifts rainfall and temperature patterns worldwide and adds heat to the global average. The current event is exceptionally strong: the Niño 3.4 anomaly of 3.21°C above average in October is the highest monthly value ever recorded in the region, surpassing the peaks of previous very strong El Niño events. The October bulletin confirms it is still intensifying rather than fading.

On 31 October 2026, World News Daily Hub published post #566, "October 2026 on Track to Be the Hottest October Ever Recorded as Super El Niño Kicks In," based on a preview estimate published on 30 October by Scientific American, which drew on a projection by climate scientists Andrew Dessler and Zeke Hausfather from partial-month Copernicus data. That estimate put October at about 1.76°C above pre-industrial levels. This article reports the official bulletin instead: it confirms the record at 1.75°C on complete data and adds the annual findings the preview could not — a virtually certain second year above 1.5°C, a most-likely second-warmest ranking, and the all-time high Niño 3.4 anomaly.

This article also differs from other recent climate coverage on this blog. Post #449, on 28 October, reported that September 2026 was the second-warmest September on record; post #614 covered an earlier El Niño record, when the Niño 3.4 anomaly reached 2.88°C, a figure now surpassed by October's 3.21°C. Post #682 covered ozone pollution, Post #851, on 6 November, reported on El Niño-linked flooding in the Horn of Africa, and Post #865, also on 6 November, covered the COP30 Leaders' Summit in Belém. This article does not revisit that summit.

Illustration: Warm surface water spreads across the tropical Pacific as an exceptionally strong El Niño intensifies.

Why It Matters

The 1.5°C threshold is not an arbitrary number. Scientists say warming beyond 1.5°C sharply increases the risk of severe heatwaves, droughts, floods and other climate impacts, as Reuters noted. Every fraction of a degree adds heat to the atmosphere, and a hotter atmosphere holds more moisture, which can mean heavier rainfall in some places and deeper drought in others. The year 2026 has already shown both faces of that risk: deadly floods in Nepal, searing heatwaves in Europe and major wildfires in Indonesia, all in a year now almost certain to end above 1.5°C, according to Reuters.

The ocean records matter for a similar reason. Sea surface temperatures are not an abstract statistic: warm oceans fuel stronger storms, bleach coral reefs, disrupt fisheries and shift rainfall patterns that farmers depend on. An October sea surface temperature of 20.95°C outside the polar regions, the highest ever recorded for the month, means the oceans are holding more heat than at any comparable point in the observational record — and that extra heat feeds back into weather systems worldwide.

The El Niño signal is the most immediate concern. An exceptionally strong El Niño rearranges rainfall across the tropics, typically bringing heavy rain and flooding to some regions and drought to others. The same event has already been linked to flooding in the Horn of Africa, as reported on this blog on 6 November, and its effects tend to peak in the months after the ocean warming reaches its maximum. With the Niño 3.4 anomaly at an all-time high and still rising, the coming months are likely to bring further extremes in the regions most exposed to El Niño's influence.

There is also a longer-term signal in the four-year average. Scientists have long warned that individual years above 1.5°C would arrive before the long-term average did, but a four-year average from 2023 to 2026 expected to exceed the mark narrows the distance between a single hot year and a sustained breach. It does not mean the goal has failed — emissions cuts can still slow warming — but the margin for delay has effectively disappeared. The findings arrive just as governments prepare to meet at COP31, and they will be difficult for negotiators to ignore, because they come from the EU's official climate monitor.

What Happens Next

The COP31 climate talks open on Monday, 9 November 2026, in Antalya, Turkey, and run until 20 November, under a joint Turkish-Australian presidency, with a World Leaders' Summit scheduled for 11–12 November. Negotiators arrive with the Copernicus findings fresh in mind and with national climate plans that, according to a United Nations synthesis published on 27 October, point to emissions in 2035 only about 6 percent below 2019 levels — far short of the roughly 60 percent cut that a pathway consistent with 1.5°C requires. Finance for adaptation, the energy transition and support for vulnerable countries are expected to dominate the agenda.

Illustration: A climate summit hall in a Mediterranean coastal city, ahead of the COP31 talks opening in Antalya on Monday, 9 November 2026.

Copernicus will publish its final annual figures early in 2027, confirming whether 2026 finished as the second-warmest year on record or, against the roughly 20 percent odds, tied or beat 2024. In the meantime, the US National Oceanic and Atmospheric Administration has put the chance of a strong to very strong El Niño continuing into early 2027 at greater than 83 percent, according to reporting this week. The November bulletin will show whether the run above 1.5°C extends to a fourth month.

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Frequently Asked Questions

Does 2026 passing 1.5°C mean the Paris Agreement target has failed?

No. The Paris Agreement's 1.5°C goal refers to a long-term average, typically measured over decades, so a single calendar year above the mark does not mean the target has been breached. But the long-term average is closing in on the limit: 2026 will be the second calendar year above 1.5°C after 2024, and the four-year average from 2023 to 2026 is also expected to exceed it. Emissions cuts can still defend the target, but the margin for delay has narrowed sharply.

How is this article different from the 31 October article about the hottest October?

Post #566, on 31 October, was based on a 30 October Scientific American preview estimate from partial-month Copernicus data, putting October at about 1.76°C above pre-industrial levels. This article reports the official Copernicus bulletin, confirming the record on complete data at 1.75°C. It also adds findings the preview could not contain: a virtually certain second year above 1.5°C, a roughly 80 percent chance of ranking second-warmest, and the all-time high Niño 3.4 anomaly of 3.21°C.

What is El Niño, and why is this one so strong?

El Niño is a natural warming of surface waters in the central and eastern tropical Pacific that shifts rainfall and temperature patterns worldwide. The current event is exceptionally strong: in October, the sea surface temperature anomaly in the Niño 3.4 monitoring region reached 3.21°C above average, the highest monthly value ever recorded there.

Could 2026 still beat 2024 as the warmest year ever recorded?

Possible but unlikely: Copernicus put the chance of 2026 tying or exceeding 2024, the warmest year on record, at about 20 percent, and the chance of ranking second at about 80 percent. The predicted range for the 2026 annual average is 1.56°C to 1.61°C above the pre-industrial level. The final ranking will be confirmed when Copernicus publishes its full-year figures early in 2027.

What will the COP31 talks in Antalya decide?

COP31, the 31st UN climate conference, opens on Monday, 9 November 2026, in Antalya, Turkey, and runs until 20 November, under a joint Turkish-Australian presidency. The talks are expected to focus on implementation: climate finance, adaptation support and the energy transition. A UN synthesis published on 27 October found current national plans point to only about a 6 percent emissions cut by 2035.

Sources

• Copernicus Climate Change Service — "October 2026 Climate Bulletin," 5 November 2026. https://climate.copernicus.eu/climate-bulletin
• Reuters — "After warmest October on record, 2026 is likely to exceed 1.5 C above pre-industrial level, says EU climate service," 6 November 2026. https://www.reuters.com/sustainability/cop/after-warmest-october-record-2026-is-likely-exceed-15-c-above-pre-industrial-2026-11-06/
• Agence France-Presse, via Sowetan — "Warmest October on record, 2026 likely to exceed critical heat measurement," 6 November 2026. https://www.sowetan.co.za/news/world/2026-11-06-warmest-october-on-record-2026-likely-to-exceed-critical-heat-measurement/
• Anadolu Agency, via Daily Imroz — "Global temperatures in 2026 set to rank second-warmest on record," 6 November 2026. https://dailyimroz.com/news/global-temperatures-in-2026-set-to-rank-second-warmest-on-record
• UNFCCC — "COP31," conference information. https://unfccc.int/cop31
• Natural History Museum — "COP31: All you need to know about the climate change conference," 23 October 2026. https://www.nhm.ac.uk/discover/cop-all-you-need-to-know-about-the-climate-change-conference.html