London: May 2026 marked a significant milestone as it ranked as the second warmest May globally since the commencement of official records. This development was accompanied by remarkable temperature anomalies in both oceanic and terrestrial environments, alongside an unusually early heat wave sweeping across western Europe, as reported by the Copernicus Climate Change Service (C3S) within the European Centre for Medium-Range Weather Forecasts (ECMWF).
According to Anadolu Agency, the global average surface air temperature in May was recorded at 15.81°C (60.45°F). This figure stands 0.55°C above the 1991-2020 average, surpassed only by May 2024. Sea surface temperatures hovered near historic highs, with the tropical Pacific evidencing strong warming trends indicative of an emerging El Ni±o phenomenon.
Europe saw a dramatic transition from cooler-than-average conditions to extreme heat during the latter half of the month. Western Europe, encompassing nations such as France, the United Kingdom, Ireland, and Portugal, experienced one of the most intense early-season heat waves on record, breaking numerous temperature records for May. "Feels-like" temperatures soared between 35°C and 40°C in various regions, precipitating severe heat-stress conditions.
Samantha Burgess, the strategic lead for climate at ECMWF, highlighted the rapidity with which climate extremes are becoming commonplace. The early and intense heat wave in Europe is emblematic of this trend, signaling a shift towards extremes becoming the norm rather than exceptions. In contrast, while western and southern Europe, including Spain and Italy, experienced drier-than-average conditions, flooding incidents were reported in Trkiye, Bulgaria, and Moldova.
The report also noted that northern Europe and parts of Scandinavia recorded wetter-than-average conditions. This contrasts with the widespread dryness observed across central and eastern Europe, where major river basins like the Danube and Vistula experienced below-average flows. Globally, wetter-than-average conditions were observed in northern and southeastern North America, sections of Asia, western China, Brazil, southern Africa, and Australia. Conversely, drought-like conditions prevailed in the central United States, much of South America, Madagascar, and southwestern Australia.
Furthermore, Arctic sea ice extent in May was approximately 4% below average, marking the fourth lowest on record for the month. In the Antarctic, sea ice levels were around 9% below average, ranking as the seventh lowest for May, with particularly low coverage noted in the Bellingshausen Sea.