The datasets line up: the last 11 years have been the 11 warmest in the modern era – WMO
By the Climate Centre
The World Meteorological Organization today confirmed that 2025 was one of the three warmest years on record, continuing a streak of extraordinary global temperatures.
The global average surface temperature last year was 1.44°C above the 1850–1900 average, according to WMO’s consolidated analysis of eight datasets – all show the past eleven years as the eleven warmest.
“The year 2025 started and ended with a cooling La Niña and yet it was still one of the warmest years on record globally because of the accumulation of heat-trapping greenhouse gases in our atmosphere,” said WMO Secretary-General Celeste Saulo.
“High land and ocean temperatures helped fuel extreme weather: heatwaves, heavy rainfall and intense tropical cyclones, underlining the vital need for early warning systems.”
Ocean temperatures
WMO’s announcement was timed to coincide with the release of global temperature reports from the various dataset providers, which include the European Center for Medium Range Weather Forecasts, the Japan Meteorological Agency, NOAA, the British Met Office and others.
A separate study published in Advances in Atmospheric Sciences said that ocean temperatures were also among the highest on record in 2025, reflecting their long-term accumulation of heat within the climate system; almost all the excess heat from global warming is stored in the oceans, making them a key indicator of climate change.
WMO says will provide full details of greenhouse gases, surface temperatures, ocean heat, rising sea levels, retreating glaciers and sea ice in its State of the Global Climate 2025 report this March.
The WMO statement came mid-way through the week-long meeting in Oslo of contributing authors to the IPCC Special Report on Climate Change and Cities – part of the seventh assessment cycle of the global climate and scheduled for release in early 2027.
The meeting in Oslo included Climate Centre Chair Debra Roberts, and Julie Arrighi, Director of Programmes.
Climate budget
As a city, the Norwegian capital is seen as a pace-setter for turning climate goals into concrete results – from zero-emission construction sites and green transport to climate-smart urban planning.
Oslo became the first city in the world in 2016 to introduce a climate budget, providing an overview of emissions as well as actions needed to reduce them.
Since 2009 it has reduced its emissions by at least 30 per cent, and the climate budget has become an important management tool, according to an article Tuesday by the Bergen-based Bjerknes Centre for Climate Research.
For his part, IPCC Chair Jim Skea said on social media after meeting Norway’s Climate and Environment Minister, Andreas Bjelland Eriksen, that the UN body he leads plays a vital role in guiding global action on climate, and that “trusted, policy-relevant science remains key to ambitious and inclusive solutions to address climate change.”
The Norwegian Environment Agency and the IPCC Monday invited cities report authors and others to an open seminar in the Oslo’s city hall. (Photo: Ellen Viste/Bjerknes Centre for Climate Research)