A Strong El Niño Could Push Climate Extremes Into 2027: Record Seas, Melting Glaciers and Heat
The WMO State of the Climate Update 2026 says the past 12 years (2015 to 2026) have all been the warmest on record, and the last four years (2023 to 2026) are the hottest ever recorded.
The global temperature for January to September 2026 was about 1.47°C (± 0.13°C) above the 1850–1900 average, based on nine international datasets. This is close to the full-year figures for 2025 (1.43°C) and 2023 (1.46°C), and below the 2024 record (1.55°C).
A strong El Niño (a natural warming of the tropical Pacific Ocean) is expected to peak around December and last into early 2027. The WMO notes that El Niño usually adds about 0.1°C to 0.2°C to the global yearly temperature, so the final 2026 figure is likely to be higher.
Sea level reached its highest point on record in 2026. Glaciers kept shrinking: the ice lost in 2025 would fill five Olympic swimming pools every second of the year. Freshwater stored on land has been falling since 2014.
In late August 2026, a glacier collapse near the Nepal–China border set off a catastrophic flash flood downstream. The WMO update puts the toll at more than 1,300 lives, with a heavy blow to Nepal's economy. In India, about 146.5 million people were exposed to extreme heat in an April 2026 heatwave.
The WMO calls El Niño a "risk multiplier" for health: more heat, drought and heavy rain can raise heat illness, smoke and poor air, malnutrition, and water-borne and mosquito-borne diseases. The World Health Organization has, for the first time, classified these expected health impacts as a health emergency.
El Niño–Southern Oscillation (ENSO)
El Niño–Southern Oscillation, or ENSO, is a natural climate swing in the tropical Pacific Ocean. Every few years the sea surface in the central and eastern Pacific becomes unusually warm (El Niño) or unusually cool (La Niña), and the air pressure and winds above it change too (the Southern Oscillation). Because the Pacific is so large, these changes shift rainfall and temperature patterns across the world, including India's monsoon.
The WMO expects the current El Niño to peak around December and continue into early 2027. Coming on top of record human-caused warming, it is why the WMO warns of more heatwaves, droughts and extreme rain in the months ahead.
Sea Level Rise: Causes, Measurement, and IPCC Projections
Sea level rise means the average height of the world's oceans is going up over time. It is happening mainly because the Earth is warming. Warm water takes up more space, and melting ice on land pours extra water into the sea. Even a rise of a few centimetres matters, because it makes storm floods reach further inland and lets salt water creep into farms and drinking water.
The WMO update reports record sea level in 2026, record ocean heat for a tenth year and continued glacier loss. These are the two biggest drivers of sea level rise (warming water and melting land ice), and a strong El Niño that keeps temperatures high into 2027 adds to the pressure.
Glacial Lake Outburst Flood (GLOF)
A Glacial Lake Outburst Flood (GLOF) is a sudden, very powerful flood that happens when water held in a lake near a glacier bursts out. These lakes are often held back by loose piles of rock and ice (called moraines) that can fail suddenly after an avalanche, landslide, earthquake or heavy rain. Glacier collapses and ice-rock avalanches are related high-mountain hazards that can trigger similar sudden floods downstream, as warming weakens glaciers in the Himalaya.
The late-August 2026 glacier collapse and flash flood on the Nepal–China border, which the WMO counts among the year's deadliest events, shows how warming is making high-mountain floods more frequent and dangerous, a direct risk for India's Himalayan states.
- 2015–2026: warmest 12 years on record; 2023–2026 the four hottest
- January to September 2026: 1.47°C ± 0.13°C above 1850–1900 (nine datasets)
- Full-year averages: 2023: 1.46°C, 2024: 1.55°C (record), 2025: 1.43°C
- El Niño adds about 0.1–0.2°C to annual global temperature; current event expected to peak around December and last into early 2027
- Ocean absorbs about 90% of excess heat; 2026 on course for a tenth straight year of record ocean heat
- Glacier ice lost in 2025 equal to five Olympic pools every second; land freshwater storage falling since 2014
- 146.5 million people in India exposed to extreme heat (April 2026)
- WHO classified El Niño's expected health impacts as a health emergency for the first time