May 2025 global temperatures
The global average surface air temperature was 15.79°C, which is 0.53°C above the 1991–2020 average and nearly 1.5°C above the 1850–1900 pre-industrial baseline. While this data breaks a months-long streak of record highs, there is little to celebrate. Twenty-one of the past 22 months have seen global temperatures exceed 1.5°C above pre-industrial levels, a threshold tied directly to the widespread use of fossil fuels. Scientists expect the slight drop to be temporary.
“May 2025 breaks a long series of months above the 1.5°C threshold compared to pre-industrial levels, a sequence we had never seen before. While this may appear to offer the planet a brief respite, we still expect that the 1.5°C mark will be exceeded again soon due to the ongoing global warming trend,” said Carlo Buontempo, director of C3S.
May 2025 heat records in Greenland and Iceland
Also in May 2025, human-induced global warming caused record-breaking heat in Iceland and Greenland, posing serious risks to local societies and ecosystems. Greenland’s ice sheet melted at a rate well above normal during the recent heatwave, according to separate research from the World Weather Attribution group.
On May 15, the airport in Egilsstaðir, Iceland, recorded 26.6°C, surpassing the previous temperature record. Other regions reported temperatures up to 10°C above average. Local ecosystems, adapted to cold climates, are especially vulnerable to rapid shifts in temperature. The disruption of these fragile balances brings harmful consequences for both nature and the communities that depend on it.
In Greenland and Iceland, infrastructure is built for cold weather. During heatwaves, melting ice creates serious threats to roads and critical systems. As the Greenland ice sheet melts, it discharges massive volumes of freshwater into salty oceans. Scientists warn this could slow down the ocean current that circulates water from the Gulf of Mexico across the Atlantic to Europe and the Arctic. A slowdown may disrupt, then alter global climate and weather patterns. Changing ocean temperatures also shift fish populations, impacting marine ecosystems and the economy.
Spring 2025 climate trends from Copernicus
Copernicus data shows that the 2025 boreal spring (March through May) was also the second-warmest on record, just behind 2024, with a temperature 0.59°C above the 1991–2020 seasonal average. Overall, temperatures were above average, especially in the Northern Hemisphere.
Spring in Europe showed mixed conditions. Northern and western Europe experienced drier-than-average weather, while southern Europe and northwestern Russia were wetter. The average temperature for Europe in May 2025 was 12.98°C, or 0.29°C below the 1991–2020 average for the same month.
Temperature patterns across Europe were sharply divided. Eastern Europe, eastern Italy, the Balkans, and Finland were cooler than average, while western Europe was warmer. Outside the continent, significantly above-average temperatures were recorded in western Antarctica, much of the Middle East, western Asia, northern Russia, and northern Canada. Conversely, parts of India, Alaska, southern Africa, and eastern Antarctica experienced cooler-than-expected temperatures for the time of year.