Bonn, 11/06/2025
Global Temperatures
- 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
*Datasets other than ERA5 may not confirm the 21 months above 1.5°C highlighted here, due to the relatively small margins above 1.5°C of ERA5 global temperatures observed for several months and differences among the various datasets.
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.
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.
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.
End -
More information about climate variables in May and climate updates of previous months as well as high-resolution graphics can be downloadedhere.
Other useful links:Answers to frequently asked questions regarding temperature monitoring can be foundhere.
Follow near-real-time data for the globe on Climate Pulsehere.
More on trends and projections on Climate Atlashere.
Access key datasets easily with the new tool ERA Explorer Apphere.
Temperature and hydrological maps and data are from ECMWF Copernicus Climate Change Service’s ERA5 and ERA5-Land (surface soil moisture) datasets. The findings about global sea surface temperatures (SSTs) presented here are based on SST data from ERA5 averaged over the 60°S–60°N domain. Note that ERA5 SSTs are estimates of the ocean temperature at about 10m depth (known as foundation temperature). The results may differ from other SST products providing temperature estimates at different depths. Sea ice maps and data are from a combination of information from ERA5, as well as from the EUMETSAT OSI SAF Sea Ice Index v2.2. Regional area averages quoted here are the following longitude/latitude bounds: Globe, 180W-180E, 90S-90N, over land and ocean surfaces. Europe, 25W-40E, 34N-72N, over land surfaces only.
Theriver flowsimulation data are calculated by the European Flood Awareness System (EFAS) as part of the Copernicus Emergency Management Service (CEMS).
Information on national records and impacts is based on national and regional reports. For details see the respective temperature and hydrological C3Sclimate bulletinfor the month.
C3S has followed the recommendation of the World Meteorological Organization (WMO) to use the most recent 30-year period for calculating climatological averages and changed to the reference period of 1991-2020 for its C3S Climate Bulletins covering January 2021 onward. Figures and graphics for both the new and previous period (1981-2010) are provided for transparency.
More information on the reference period used can be foundhere.
More information on Copernicus:www.copernicus.eu
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SURFACE AIR TEMPERATURE FOR MAY 2025
HYDROLOGICAL VARIABLES FOR MAY 2025
SEA ICE COVER FOR MAY 2025