A record-breaking heatwave, said to be the worst-ever to affect the region, disrupted daily life across much of Western Europe, including the British Isles, in late June 2026. The deadly heatwave originated in the Iberian Peninsula and then spread to Western Europe, Central Europe and the Balkans, and elsewhere in Southern Europe. High temperatures, rising to as much as 10 to 150 C higher than normal, and high humidity, as measured by wet bulb globe temperatures, caused “red alerts” to be issued in France, Germany, Italy, the Netherlands, Switzerland, and the UK. The UK’s red alert was only the second-ever to be issued, following July 2022. It should be noted that June is normally not the hottest month of the year in the UK. According to the Met Office, the UK’s national meteorological service, “a UK heatwave threshold is met when a location records a period of at least three consecutive days with daily maximum temperatures meeting or exceeding the heatwave temperature threshold”, which varies by UK county in the range of 25-280 C. Europe is said to be the fastest-warming continent, having warmed twice as fast as the global average since the 1980s. Temperatures in Europe have risen by around 2.50 C above pre-industrial levels.
During the heatwave, schools closed, rail services were delayed or cancelled, open-air events were called off, emergency calls to ambulance services surged, and hospitals struggled to cope with increased demand. People were asked to avoid non-essential travel and to work from home wherever possible. Public shelters and hydration facilities were provided for those who had to brave the heat for whatever reason. Increased demand on electricity grids caused power outages, compounding the effects of the heatwave. Essential outdoor workers, including those working on construction sites, were put at risk of heat stress. Some unfortunate people, including many children, drowned as they attempted to escape the overbearing heat by immersing themselves in public expanses of water. There was no respite during the nights, which stayed warm and humid, interfering with sleep and impeding recovery from the effects of daytime heat exposure.
Heatwaves are considered ‘extreme weather events.’ Such events have become more frequent, longer in duration, and more severe due to climate change. Severe heatwaves in Europe are in keeping with global trends, whereby the years from 2015 to 2025 have become the warmest on record, as judged by measurements of global combined, annually averaged, land and ocean temperatures. The latest heatwave has been attributed to a powerful heat dome- a high-pressure system over Western Europe which acted as a lid and trapped hot air underneath, while simultaneously drawing in warm air from Northern Africa. In some areas, wildfires, localised thunderstorms, and flash floods complicated the already dire situation.
The Western European heatwave has tested heat resilience in a part of the world used to cold winters and mild summers, and thus less able to cope with high environmental temperatures, made even more intolerable by coexisting high humidity. Local inhabitants are particularly susceptible to the deleterious effects of high temperatures on both animal and human health. Dehydration and heat-related illness, the most severe manifestation of which is heatstroke, can prove to be a lethal combination, responsible for otherwise preventable deaths. Heat stress poses greater risks to people at the extremes of age, outdoor workers, homeless people, pregnant women, and those with chronic illnesses. Despite the potential risks to life, many people, especially the young and healthy, seem to welcome hot weather and appear to be unaware of, or unconcerned about, the downsides.
Although some influential political leaders, business leaders with conflicts of interest, and various ideologists with different axes to grind continue to deny the possibility of human-driven climate change, the consensus of scientific opinion indicates that the latest heatwave can be attributed to anthropogenic global warming. To prepare for the future, shorter-term measures such as early warning systems, coordinated heat-health action plans, lifestyle modifications, and the considered installation of air- conditioning units (which, unfortunately, consume electricity and add to energy costs) will need to be complemented by longer-term attention to urban landscape redesign and efforts at preventing buildings from overheating by making them cooler and more heat-resilient. Bold action, backed by wisely-spent money, is called for.
Ashis Banerjee