Rising global temperatures are increasingly being linked to the growing frequency and intensity of extreme weather events, including heatwaves, heavy rainfall, and powerful tropical cyclones, the World Meteorological Organization (WMO) has reiterated.
According to the UN climate body, the past 11 years, from 2015 to 2025, rank as the 11 warmest years on record, emphasizing an alarming and sustained warming trend. WMO has confirmed that 2025 was among the three warmest years ever recorded, despite beginning and ending under cooling La Niña conditions.
Based on a consolidated analysis of up to eight global temperature datasets, WMO found that the global average surface temperature in 2025 was 1.44°C above the 1850–1900 pre-industrial average, with a margin of uncertainty of ±0.13°C.
Even more concerning, the three-year period from 2023 to 2025 represents the warmest three-year span across all eight datasets, with average temperatures reaching 1.48°C above pre-industrial levels.
WMO Secretary-General Celeste Saulo emphasized that the continued rise in temperatures highlights the urgent need to cut carbon emissions.
“The fact that 2025 was one of the warmest years on record, even with La Niña conditions, clearly shows the impact of accumulated heat-trapping greenhouse gases in our atmosphere,” Saulo said.
The datasets used in the analysis include observations from the European Centre for Medium-Range Weather Forecasts’ Copernicus Climate Change Service (ERA5), Japan Meteorological Agency (JRA-3Q), NASA (GISTEMP v4), NOAA (NOAAGlobalTemp v6), the UK Met Office in collaboration with the Climatic Research Unit at the University of East Anglia (HadCRUT 5.1.0.0), and Berkeley Earth.
For the first time, WMO also incorporated two additional datasets: the Dynamically Consistent Ensemble of Temperature (DCENT) and the China Merged Surface Temperature Dataset (CMST).
Six of the datasets are based on direct measurements from weather stations, ships, and ocean buoys, with statistical methods used to address data gaps. The remaining two, ERA5 and JRA-3Q, are reanalyses that combine historical observations, including satellite data, with climate models to produce consistent long-term climate records.
Saulo noted that this collaborative and scientifically rigorous approach to climate monitoring is more critical than ever, particularly as early warning systems and climate resilience efforts depend on reliable international data exchange.
“Earth information must be authoritative, accessible, and actionable for all,” she said.
Despite slight differences in methodologies and annual rankings among the datasets, the overall trend remains unequivocal: the planet is warming at a dangerous pace.
Bill Hare, CEO and Senior Scientist at Climate Analytics, warned that the WMO findings demonstrate governments’ failure to act with sufficient urgency.
“With this level of warming, we are seeing relentless climate disasters worldwide, from floods and heatwaves in South and Southeast Asia to powerful hurricanes in the Caribbean, while insurance costs continue to skyrocket,” Hare said.
He added that analysis by the Climate Action Tracker shows that fully implementing already agreed global commitments could significantly reduce future warming.
“If governments deliver on their existing pledges, projected warming could be reduced by nearly one degree, bringing the world within 0.2–0.3°C of limiting warming to 1.5°C or below,” Hare noted.
These commitments include tripling renewable energy capacity, doubling energy efficiency, and sharply cutting methane and other greenhouse gas emissions.
Hare stressed that while time remains to avert the worst impacts, meaningful progress depends on bold political action.
“Our modelling shows that a ‘highest possible ambition’ pathway still exists to return global temperatures to well below 1.5°C this century. But this will only happen if governments move beyond incremental steps to rapid implementation, supported by scaled-up finance for vulnerable and poorer countries,” he said.
