The year 2025 is set to be among the top three hottest years in the planet’s 176-year observational record, according to the State of the Global Climate Update from the World Meteorological Organization (WMO).

The mean near-surface temperature from January to August was 1.42°C (± 0.12°C) above the pre-industrial average, the report said.

Depending on what the final mean temperature would be by the end of December, 2025 is likely to end up as the second or the third warmest year on record.

WMO’s report comes days before the UN climate summit COP30, set to kick off on Monday in Brazil’s Belém, and is meant to provide evidence to anchor the climate negotiations.

“This unprecedented streak of high temperatures, combined with last year’s record increase in greenhouse gas levels, makes it clear that it will be virtually impossible to limit global warming to 1.5°C in the next few years without temporarily overshooting this target,” said WMO Secretary-General Celeste Saulo.

“But the science is equally clear that it’s still entirely possible and essential to bring temperatures back down to 1.5°C by the end of the century.”

See related story: World on Track for 2.8°C Warming as Paris Agreement Overshoot Now Inevitable

Concentrations of heat-trapping greenhouse gases and the ocean heat content, which reached record levels in 2024, have continued to rise in 2025. The past 11 years (2015-2025)  will individually have been the 11 warmest years on record.

“Each year above 1.5°C will hammer economies, deepen inequalities and inflict irreversible damage. We must act now, at great speed and scale, to make the overshoot as small, as short, and as safe as possible – and bring temperatures back below 1.5°C before the end of the century,” said UN Secretary-General António Guterres, who also cited the WMO report in his statement to the upcoming COP30, imploring countries to be more ambitious in their actions.

As temperature rise continues, Arctic and Antarctic ice hit record lows 

In 2024, the current hottest year on record, the mean near-surface temperature was 1.55°C (± 0.13 °C). It temporarily breached the 1.5°C target set by the 2015 Paris Agreement. 

The 26-month period from June 2023 to August 2025 has seen an extended streak of monthly record-breaking temperatures, with February 2025 being an exception.

WMO has attributed the global temperatures in the past three years to the transition from a prolonged La Niña that lasted from 2020 to early 2023 to El Niño conditions. In addition, reductions in aerosols and other factors have likely also played a role in increasing the warming, WMO report said.

About 90% of the excess heat in the Earth’s atmosphere goes into the oceans. As a result, ocean heat content has continued to rise in 2025, according to preliminary data, and is above the record 2024 values. 

The rising temperatures have affected the ice volume at both poles.

Arctic sea-ice extent reached its annual maximum of 13.8 million km2 in March, the lowest maximum extent in the satellite record. Arctic sea-ice extent reached its annual minimum of 4.6 million km2 around 6 September, which remained below the long-term average.

Antarctic sea-ice extent was the third lowest on record, both for the annual minimum (2.1 million km2) in February 2025, and annual maximum (17.9 million km2) in September 2025.

All monitored glaciated regions around the world recorded net mass loss in the hydrological year 2023-24.

The long-term sea level rise trends continue despite a small and temporary blip due to naturally occurring factors.

Cascading impact of long-term temperatures continue

Rising temperatures have a cascading impact on extreme weather events, such as devastating rainfall and flooding to brutal heat and wildfires.

Until August, such events contributed to displacement across multiple regions, undermining sustainable development and economic progress.

But the WMO has highlighted progress made when it comes to early warning systems. Since 2015, the number of countries reporting multi-hazard early warning systems (MHEWSs) has more than doubled – from 56 to 119 in 2024.

Nearly 40% countries still lack MHEWSs, and WMO is pushing for regional collaborations to close these gaps. This was also a key focus area at its recently concluded Congress in Geneva.

Countries are also using weather and climate data for seasonal outlooks in key sectors like agriculture, water, health and energy. Around two-thirds of countries now provide some form of climate services, varying from essential to advanced level. This number was at 35% just five years ago, WMO said.

The organisation has cautioned that, given climatic changes would influence the production of renewable energy, countries need to factor these influences to build reliable and flexible clean energy systems.

Image Credits: Unsplash/Misbahul Aulia, WMO.