2026 Among Hottest Years: Super El Niño Threatens More Climate Extremes in 2027

The past 12 years are the warmest recorded, and 2023 through 2026 are expected to occupy the four highest positions, showing how persistent human-driven warming has become.

The world faces another year of climate extremes, with 2026 on track to rank among the four hottest years recorded and a powerful El Niño threatening more disruption into 2027, the World Meteorological Organization (WMO) warns. State of the Climate Update 2026, released at COP31 in Antalya, Türkiye, describes record ocean heat, rising seas, melting ice and weather disasters affecting lives and economies. Data from January to September put global temperatures about 1.47°C above the 1850–1900 average, with the developing El Niño expected to lift the final annual figure.

The past 12 years are the warmest recorded, and 2023 through 2026 are expected to occupy the four highest positions, showing how persistent human-driven warming has become. Early-year La Niña briefly cooled the planet, before El Niño strengthened from August and raised fears of a record-strong event by December. The natural climate pattern releases stored ocean heat into the atmosphere and can add roughly 0.1°C to 0.2°C to global average temperatures, often with its strongest effect the following year.

The report links worsening heatwaves, floods, droughts and cyclones to growing threats to food, health, water supplies and livelihoods, especially in communities with limited resources. UN Secretary-General António Guterres called for faster emissions cuts, a fair move away from fossil fuels and greater financial support for countries facing the greatest climate harm. WMO chief Celeste Saulo cautioned that an unusually warm ocean gives El Niño more heat to redistribute, increasing risks beyond what historical experience has prepared many communities to face.

Record Ocean Heat and Rising Seas Signal Growing Climate Pressure

Greenhouse gases are trapping more heat, driving Earth's energy imbalance to a record in 2025, with preliminary measurements pointing to another high in 2026. Carbon dioxide reached roughly 426.8 parts per million in 2025, 53% above preindustrial levels, with methane and nitrous oxide also reaching records. Oceans absorb about 90% of the excess heat, and 2026 was on course to become the tenth consecutive year of record ocean warmth, placing marine life under growing strain.

Ocean temperatures and expansion of warming seawater, combined with melting land ice, pushed average sea levels to a record in 2026, with particularly high readings from June through August. Preliminary measurements also showed that heat stored in the upper 2,000 metres of the ocean continued increasing, reinforcing the risks of damaging storms and changes to marine ecosystems. Some effects will persist for centuries, making today's warming a concern for coastal communities far beyond the present El Niño event.

Melting Glaciers and Declining Freshwater Threaten Communities

Antarctic sea ice reached its third-lowest annual maximum in the satellite record during 2026, and the Arctic maximum ranked as the lowest or second-lowest, threatening habitats and altering climate processes. Glaciers lost more than 400 billion tonnes of ice in 2025, equivalent to filling five Olympic swimming pools every second for a year and adding roughly one millimetre to global sea levels. All 19 monitored glacier regions recorded losses for a fourth consecutive year, increasing concerns about mountain hazards and the availability and quality of water downstream.

Global water stored in soils, rivers, groundwater, snow and glaciers has been declining since 2014, adding pressure to agriculture and communities reliant on predictable seasonal supplies. In 2025, 42% of assessed land areas had below-normal water storage, far above the long-term average of 25%, according to the WMO update. Such losses create serious challenges for farming regions and communities already facing water shortages.

Deadly Weather Disasters Increase the Need for Early Warning Systems

Europe's 2026 heatwaves, drought and wildfires were linked to more than 30,000 excess deaths in preliminary estimates, with at least eight countries setting national temperature records. An April heatwave exposed an estimated 146.5 million people in India to extreme heat, and a Himalayan glacier collapse followed by flash flooding in Nepal killed more than 1,300 people in August. Tropical cyclones caused further casualties and destruction across several countries, disrupting transport, agriculture and livelihoods.

El Niño may increase risks of heat illness, wildfire smoke, food insecurity and diseases such as cholera, malaria and dengue as heat, drought and heavy rainfall affect communities. The report says the World Health Organization has classified the expected health impacts as a health emergency, and it warns that rain-dependent farming in food-insecure regions is particularly vulnerable. Reliable weather monitoring and accessible alerts are crucial, with the number of countries reporting multi-hazard early warning systems rising from 56 in 2015 to 136 in 2025.

The WMO update uses data available through September 2026 and does not capture the latest El Niño impacts, with a fuller global climate report due in March 2027. Governments will need these observations to prepare for further extreme weather and reduce the human and economic costs of a warming planet. The report makes clear that the coming months will test how effectively governments turn climate forecasts into practical protections for the communities most at risk.