WMO says 2026 will be one of the four warmest years on record as El Niño strengthens

The World Meteorological Organization (WMO) said on November 9, 2026, that this year will be one of the four warmest on record, and that a very strong El Niño is likely to bring more heat and extreme weather well into 2027. Its State of the Climate Update 2026, released on the first day of the UN climate conference COP31 in Antalya, Türkiye, puts the global mean near-surface temperature for January to September at 1.47°C above the 1850-1900 average, give or take 0.13°C. That is about 2.6°F, by our conversion. The update uses data up to September where available, so WMO cautions that it does not yet show the latest effects of El Niño.

WMO compares the nine-month figure with whole years: it is close to the averages for 2025 (1.43°C) and 2023 (1.46°C) and below the 2024 record of 1.55°C. The agency says the four years from 2023 to 2026 are the four warmest on record, and that the 12 years from 2015 to 2026 are set to be the warmest. The estimate combines nine datasets: Berkeley Earth, CMA-GMST, CMST, DCENT-I, ERA5, GISTEMP, HadCRUT5, JRA-3Q and NOAAGlobalTemp.

Why El Niño matters for the final number

El Niño has been building since August, according to WMO, which expects it to be the strongest on record by December and to last into early 2027. Because an El Niño typically lifts annual global temperatures by around 0.1°C to 0.2°C, the report says the final figure for 2026 is likely to come in above the January-to-September average.

“El Niño doesn't add new heat to the planet. It releases heat from the ocean, which is the warmest ever measured. There is simply more heat available to release,” said WMO Secretary-General Celeste Saulo. At the launch she said that El Niño usually has its biggest effect on global temperatures in the year after it forms, which is why 2024 became the warmest year on record, and that the world should prepare for another record-breaking year in 2027. WMO declares an El Niño when sea surface temperatures in the tropical Pacific are 0.5°C above average; Saulo said the agency forecasts they may reach nearly four times that between November 2026 and January 2027. Those are forecasts, not measurements.

Oceans, ice and water

The ocean takes up 90% of the excess heat that greenhouse gases trap, according to WMO. The heat stored in its upper 2,000 meters set a record in 2025 and kept rising in 2026 on preliminary data to July, and WMO says 2026 is on track to be the tenth year in a row of record ocean heat. The planet's energy imbalance, the rate at which the Earth system gains heat, reached its highest value since monitoring began in 1960 in 2025, and preliminary figures for January to July 2026 point to another record. Global mean sea level also hit a record in 2026, with June, July and August the highest months since satellite altimetry began in 1993.

Glaciers lost more than 400 gigatons of ice in 2025, which WMO equates to about 1 millimeter of sea-level rise, and 2025 was the fourth year running in which all 19 glaciated regions lost ice. In 2026, Antarctic sea ice had its third-lowest annual maximum of the satellite era, which began in 1979, and the Arctic maximum was the lowest or second lowest. Water stored on land has been falling globally since 2014: in 2025, 42% of the area assessed had below-normal storage, against a long-term average of 25%.

Greenhouse gas concentrations, which WMO says hit a record in 2025, kept climbing in 2026, according to benchmark stations such as Mauna Loa in Hawaii and Kennaook/Cape Grim in Australia. We covered WMO's bulletin on the 2025 levels in October.

The human cost, and the warnings

The report cites preliminary estimates of more than 30,000 excess deaths from Europe's heatwaves, drought and wildfires, with national temperature records in at least eight countries. It says an April 2026 heatwave in India exposed an estimated 146.5 million people to extreme heat, and that more than 1,300 people died in a Himalayan glacier collapse and the flash flood downstream in late August, which also badly hit Nepal's economy. According to WMO, the World Health Organization has for the first time classified the health effects expected from this El Niño as a health emergency.

WMO also points to progress on warnings: 136 countries reported having multi-hazard early warning systems in 2025, up from 56 in 2015. The update is provisional. WMO plans to publish the final State of the Global Climate 2026 report, drawing on national weather services, in March 2027.