Forecasters project strongest El Niño in over a century, warning 2027 could become hottest year on record

Pacific warming reaches exceptional levels

Sea surface temperatures in the equatorial Pacific have climbed far beyond normal thresholds, with eastern basin anomalies exceeding 2 °C above average. Scientific agencies declare an El Niño event when sea temperatures rise 0.5 °C above the long-term baseline, with typical strong events reaching 1 °C to 2 °C. Data compiled by the Climate Brink panel from NOAA shows the Niño 3.4 region already measuring 2.6 °C above the 30-year average, with projections pointing toward a 3.9 °C peak in November 2026. Subsurface measurements in the Pacific reveal localized temperature anomalies reaching 8 °C to 10 °C above normal alongside a deeper thermocline. International modeling systems estimate a 69% probability that the event will surpass the intensity of all recorded episodes since 1950.

Climate scientist Thomas Frölicher explained that strong trade winds normally push warm surface water west toward Indonesia while pulling cold water from the ocean depths off South America. The weakening of these winds halts the cold upwelling, trapping thermal energy across the eastern Pacific.

Projections for global heat in 2027

During intense El Niño events, ocean heat transfers into the atmosphere over a nine-to-twelve-month cycle, elevating global surface temperatures in the subsequent calendar year. Forecasters project that 2027 will replace 2024 as the warmest year on record, temporarily exceeding pre-industrial averages by more than 1.5 °C. The warming follows European heatwaves in 2026 that pushed Swiss temperatures close to 40 °C and dropped water levels across Europe. Met Office Science Fellow Dr Nick Dunstone detailed the timeline of the global temperature response:

During large El Nino events significantly more heat is released from the ocean to the atmosphere leading to an increase in global average temperature, particularly in the calendar year following the winter peak of the El Nino. Hence, 2027 is very likely to replace 2024 as the warmest year on record and be another year to temporarily exceed plus 1.5C above the pre-industrial period.

Regional weather shifts and commodity risks

Altered atmospheric circulation will generate contrasting weather patterns across continents. Forecasters anticipate severe drought conditions across the tropics, southern Africa, north-east Australia, and regions of South America. In north-western Europe and the United Kingdom, the weather system is expected to deliver wetter and stormier conditions beginning in autumn. Potential disruptions to agricultural harvests threaten global commodity supplies, particularly for sugar, coffee, and cocoa. Met Office head of long-range forecasting Professor Adam Scaife described the scale of the observed model output:

I have never seen an El Nino signal this intense in our forecasts.

Infrastructure strains and rail adaptation

The shift in weather patterns follows dry summer conditions in Britain, where 71.3% of England and all of Wales entered drought after the driest July in 190 years. Transport infrastructure experienced stress during an August 2026 heatwave that caused two train derailments within 24 hours, leading operators to reduce speeds and timetables. University of Warwick professor Xueyu Geng noted that British tracks are designed for low temperatures down to -10 °C, whereas systems in Spain manage 0 °C to 45 °C and Saudi Arabia handles 10 °C to 55 °C through track pre-stressing. Network Rail increased its five-year expenditure on climate, earthworks, and drainage fivefold in 2024 to adapt infrastructure to shifting conditions. Met Office chief of science and technology Professor Stephen Belcher described the dual pressures on the climate system:

This summer we have experienced heat waves across Europe reminding us of the effects of climate change, this large El Nino is a reminder that natural variations in the climate system are also at play, adding to the stresses of climate change.