A powerful and unusually early heatwave has swept across western Europe this week, shattering temperature records in multiple countries and prompting health warnings, government crisis meetings, and growing concern about the human cost of extreme heat. Driven by a mass of warm air drawn up from North Africa and trapped beneath a persistent high-pressure system — commonly known as a heat dome — temperatures across parts of the continent have reached 10 to 15 degrees Celsius above what is typical for late May.
The records have fallen in rapid succession. In the United Kingdom, Kew Gardens in London hit 35.1°C on Tuesday, breaking the previous May record of 34.8°C set just the day before — itself already well above the long-standing national record of 32.8°C, which had stood since 1922. Ireland recorded its highest-ever May temperature, 28.8°C, at Killarney in the south-west and Clonmel in the south. In France, temperatures reached 36°C on Monday and Tuesday, with Angoulême in the south-west reaching 37.8°C later in the week — breaking records that had only just been set days earlier. A primary school in south-western France suspended afternoon classes after indoor temperatures climbed to 53°C; one child fainted and several others were sick. In Portugal, the central town of Mora recorded 40.3°C on Wednesday, surpassing its previous May record of 40°C set in 2001. Italy placed Rome and three northern cities under its highest-level heat alert — triggered when dangerous conditions persist for three or more consecutive days — with warnings also issued across Spain, where forecasters described temperatures as "exceptionally high" for the season. The French government convened an emergency crisis meeting and has faced criticism for insufficient public preparedness. Seven deaths in France have been linked directly or indirectly to the heat.
Beyond the physical dangers, researchers warn of a broader social toll. Psychologists note that sustained heat lowers people's tolerance for frustration, accelerates heart rate, raises blood pressure, and increases cortisol — the body's primary stress hormone. Disrupted sleep during hot nights compounds the effect. Studies cited by experts suggest that a 10°C rise in temperature is associated with a 9% increase in violent crime, while a United Nations report published in April 2025 found that each additional degree Celsius of global warming is linked to a 4.7% rise in domestic violence worldwide. Femicide rates also increase significantly during heatwaves. In France, reports of street harassment on one safety app surged 30% in the past week alone.
Scientists are clear about the underlying cause: the increasing frequency and severity of such heatwaves is a direct consequence of human-driven climate change. While temperatures are expected to remain 5 to 10°C above average for the rest of the week, forecasters anticipate a gradual easing in the UK early next week — though Portugal's weather service warned the heat could extend well into June.