May 2026 was the second warmest May globally since record-keeping began, according to the Copernicus Climate Change Service (C3S) of the European Centre for Medium-Range Weather Forecasts (ECMWF).
The global average surface air temperature reached 15.81°C in May, which was 0.55°C above the 1991-2020 average and second only to May 2024. The report said sea surface temperatures remained near record levels, while the tropical Pacific continued to warm as conditions moved toward the development of an El Nino event.
Europe experienced a sharp transition from cooler-than-average weather to extreme heat during the second half of May. Western European countries, including France, the United Kingdom, Ireland and Portugal, recorded one of their most intense early-season heatwaves, with several May temperature records broken.
In some areas, “feels-like” temperatures reached between 35°C and 40°C, creating severe heat stress conditions. ECMWF Strategic Lead for Climate Samantha Burgess said the unusually early and intense heatwave in Europe highlighted how climate extremes were increasingly becoming the norm.
The report also noted contrasting rainfall patterns across Europe. While Spain and Italy experienced drier-than-average conditions, flooding affected parts of Türkiye, Bulgaria and Moldova.
Northern Europe and parts of Scandinavia were wetter than average, while central and eastern Europe faced widespread dryness, with below-average river flows reported in major river basins, including the Danube and Vistula.
Outside Europe, above-average rainfall was recorded in northern and southeastern North America, parts of Asia, western China, Brazil, southern Africa and Australia. Meanwhile, drier-than-average conditions affected the central United States, much of South America, Madagascar and southwestern Australia.
The report further stated that Arctic sea ice extent in May was around 4 percent below average, making it the fourth-lowest May extent on record. Antarctic sea ice extent was approximately 9 percent below average, ranking as the seventh-lowest for the month.
