The Copernicus Climate Change Service (C3S) is reporting an exceptionally dry spring in parts of north-western Europe and second-warmest May globally.

Implemented by the European Centre for Medium-Range Weather Forecasts on behalf of the European Commission with funding from the EU, C3S routinely publishes monthly climate bulletins reporting on the changes observed in global surface air and sea temperatures, sea ice cover and hydrological variables.

Highlights of the bulletin for May 2025 for surface air temperature and sea surface temperature:

• May 2025 was the second-warmest May globally, with an average ERA5 surface air temperature of 15.79°C, 0.53°C above the 1991-2020 average for May.
• May 2025 was 0.12°C cooler than the record May of 2024, and 0.06°C warmer than the third warmest of 2020.
• May 2025 was 1.40°C above the estimated 1850-1900 average used to define the pre-industrial level, interrupting an extended period of 21 months (out of 22) with a global-average temperature more than 1.5°C above the pre-industrial level. 

The 12-month period of June 2024 – May 2025 was 0.69°C above the 1991-2020 average, and 1.57°C above the pre-industrial level

According to Carlo Buontempo, director of C3S at ECMWF:

"May 2025 breaks an unprecedentedly long sequence of months over 1.5ºC above pre-industrial. Whilst this may offer a brief respite for the planet, we do expect the 1.5ºC threshold to be exceeded again in the near future due to the continued warming of the climate system.”

Europe and other regions

The average temperature over European land for May 2025 was 12.98°C, 0.29°C below the 1991-2020 average for May. There was a notable contrast in surface air temperatures across Europe in May 2025, with below-average temperatures in eastern Europe from eastern Italy and the Balkans to Finland and above-average temperatures in western Europe.

Outside Europe, temperatures were most above average over western Antarctica, a large area of the Middle East and western Asia, northeastern Russia, and northern Canada. Temperatures were most below average over India, Alaska, southern Africa, and eastern Antarctica.

Seasonal highlights

The global-average temperature for the boreal spring 2025 (March to May) was the second highest on record at 0.59°C above the 1991-2020 average, and colder only than the boreal spring of 2024.

Temperatures were mostly above average, especially in the Northern Hemisphere. The largest positive anomalies were recorded over west central Asia, northeastern Russia, Greenland, and western Antarctica, while negative anomalies occurred over the Hudson Bay, southern and northeast Africa, India, northern parts of Australia, and eastern Antarctica.

Sea surface temperature

The average sea surface temperature (SST) for May 2025 over 60°S–60°N was 20.79°C, the second-highest value on record for the month, 0.14°C below the May 2024 record.

SSTs remained unusually high in many ocean basins and seas. Among them, large areas in the northeast North Atlantic, which experienced a marine heatwave, had record-high SSTs for the month. Most of the Mediterranean Sea was much warmer than average.

May 2025 – Hydrological highlights:

In May 2025, much of northern and central Europe as well as southern regions of Russia, Ukraine, and Türkiye were drier-than-average.

Conversely, conditions were wetter than average in most of southern Europe, regions of Fennoscandia, in a north-south band from the Baltic to the Black Sea and in parts of western Russia.

In May 2025, it was drier than average in much of North America, in the Horn of Africa and across central Asia, as well as in southern Australia, and much of both southern Africa and South America.

Wetter-than-average conditions were experienced in Alaska, as well as eastern USA, across Russia, north of the Indian Subcontinent, south-eastern Africa and eastern and north-western Australia.

Seasonal highlights

European spring 2025 saw a contrast between predominantly drier-than-average conditions in much of the north and west and wetter-than-average conditions across the south and in northwestern Russia.

Parts of north-western Europe saw the lowest precipitation and soil moisture levels since at least 1979.

Persistent dry conditions have led to lowest spring river flow across Europe since records began in 1992.

Beyond Europe, March to May 2025 was drier than average over western North America and extra-tropical South America, the Horn of Africa, parts of central Asia, China, and south of Australia.

Wetter-than-average conditions established over eastern North America, Alaska, across Russia, southern Africa, and northern Australia.

May 2025 – Sea Ice highlights:

• Arctic sea ice extent was only 2% below average, the 9th lowest monthly extent for May in the 47-year satellite record.
• Regionally, below-average sea ice concentrations were most pronounced along the northern coast of Eurasia (Barents, Kara, and Laptev Seas).
• Antarctic sea ice extent was 9% below average, marking its 5th lowest value on record for the month.
• Antarctic sea ice showed alternating areas of above- and below-average concentrations, shaped by the positioning of high- and low-pressure systems around the continent.

Copernicus is the Earth observation component of the European Union’s Space programme. The programme is coordinated and managed by the European Commission and implemented in partnership with the Member States and European organisations.

The European Centre for Medium-Range Weather Forecasts (ECMWF) is both a research institute and a 24/7 operational service, producing global numerical weather predictions and other data for our Member and Co-operating States and the broader community. It operates a world-class supercomputer facility for weather forecasting and holds one of the largest meteorological data archives.

ECMWF is a key player in Copernicus, the Earth Observation component of the European Union’s Space programme.

Together with ESA and EUMETSAT, ECMWF also delivers the EU’s Destination Earth initiative, which is developing prototype digital twins of the Earth.