Three major analyses of global temperature data indicate that 2026 is now “virtually certain” to rank as the warmest or second warmest year on record. Their projections also point toward an even hotter 2027 as the effects of an exceptional El Niño continue to unfold.

The findings come from the European Union’s Copernicus climate observation program, climate reporting organization Carbon Brief, and climate science nonprofit Berkeley Earth. They were released as COP 31, the 2026 United Nations Climate Change Conference, begins in Antalya, Turkey.

Countries attending the conference will discuss policies and progress toward addressing climate change. The temperature projections provide an alarming backdrop, with the organizations broadly agreeing that 2026 will rank among the two hottest years recorded.

Global temperature analyses can differ because researchers make varying decisions about how to estimate conditions in places with limited measurement coverage, including Antarctica. Those methodological differences help explain why the organizations assigned different probabilities to 2026 becoming the hottest year.

Berkeley Earth calculated a 95% chance that 2026 will be the hottest year on record. Copernicus’s ERA5 analysis placed that probability at approximately 20%, while still finding that a ranking of at least second hottest is “virtually certain”.

Carbon Brief averaged values from six datasets and incorporated forecasts and statistical analyses. It assigned 2026 a 67% chance of surpassing 2024 as the warmest year ever recorded.

“[The difference] partly turns on small nuances (hundredths of a degree) in estimating year-to-date warmth and also the previous record warmth in 2024,” Dr Robert Rohde at Berkeley Earth told IFLScience. Despite their different probabilities, the analyses point toward another exceptionally hot year.

Each projection expects the global mean temperature for 2026 to exceed 1.5°C above the average before industrialization. That would make 2026 only the second year to breach the threshold, following 2024, which averaged 1.55°C according to the World Meteorological Organization.

The WMO reported that the 2026 average through September stood at 1.47°C. It expected the figure to rise during the final two months of the year because of the effects of the ongoing record breaking El Niño event.

Carbon dioxide and other greenhouse gas emissions are overwhelmingly responsible for the planet’s long term warming. El Niño, the warm phase of a tropical Pacific climate pattern that periodically releases ocean heat into the atmosphere, adds to that warming during active years.

In September, the monthly average sea surface temperature in the Niño 3.4 region surpassed the previous record of 2.72°C from November 2015. The measurement, widely used to assess El Niño strength, remained above that previous record every day afterward.

“This El Niño event is developing so quickly and is reaching sea surface temperatures so warm that it’s simply staggering,” climate researcher Zeke Hausfather wrote while responding to Carbon Brief members online. “We haven’t seen anything like this in the historical record and it may end up being the strongest El Niño event in the past millennium.”

Nearly all forecast models expect El Niño to peak in November or December at around or below 4°C, approximately 1 degree warmer than the previous record. Because global temperatures lag behind the El Niño peak by about three months, 2027 is expected to become hotter still.

Carbon Brief projects that 2027 will finish at 1.74°C above the average before industrialization. Although the estimate has a relatively wide uncertainty range, the organization is 90% confident that the final figure will fall between 1.54°C and 1.95°C.

“This gives 2027 a 96% chance of being warmer than any previous year, including 2026. There is a 98% chance that at least one of 2026 or 2027 will set a new record,” Carbon Brief stated in its “State of the Climate” update.

The human consequences are already stark. The recent WMO report said European heatwaves were thought to have caused 30,000 excess deaths, while an estimated 146.5 million people in India were exposed to extreme heat during April.

Hausfather said precipitation shifts around the tropics were the most concerning effects associated with strong El Niño events. He identified major rainfall reductions in Indonesia, the Maritime continent, the Philippines, the Amazon, and South Africa, along with severe fires, emissions, and air pollution in Indonesia and the Amazon.

In October, the 2026 Lancet Countdown on Health and Climate Change, produced with the World Health Organization, called for climate change to be formally recognized as a global health emergency. Rohde warned, “As long as that continues, we should expect many new records.”