Denmark registered its highest temperature on record on Saturday, with the Danish Meteorological Institute confirming a reading of 36.6C north of Odense – the hottest day since measurements began in 1874. The previous national record of 36.4C, set in August 1975, has now been surpassed as a ferocious heatwave tightened its grip across Europe.
Record temperatures
The Danish milestone was just one of several records to fall over the weekend. Germany’s national meteorological service said a preliminary reading of 41.3C was recorded near the city of Saarbrücken on Friday, close to the French border. The service issued extreme heat warnings for nearly all of Germany on Saturday, forecasting temperatures of 36C across the board with local highs of 42C possible. Karsten Brandt, a meteorologist at the weather forecasting site Donnerwetter, said the heatwave was set to peak at the weekend at well over 40 degrees in parts of Germany.
Slovakia confirmed that Friday night was its warmest on record, with temperatures failing to drop below 26.3C. Britain, France, Switzerland and Germany have all experienced record heat in June, and the weather system is expected to roll eastwards towards Poland, testing further records along the way. The United Kingdom recorded its hottest ever June temperature on 27 June, reaching 36.7C in Somerset. The heatwave has been described as the worst ever recorded in Europe, with red alerts issued in Germany, Belgium, Italy, Switzerland and the Netherlands.
Impacts across Europe
The human toll has been severe. In France, dozens of people – both young and old – have died during the heatwave, and the French prime minister’s office warned that although the heatwave was moving on, pressure on the healthcare system would persist and hospitalisations would stay high for several days. Across Europe, hospitals have struggled to cope. In London, the ambulance service responded to its highest ever number of life-threatening emergencies in a single day. In Italy, emergency room admissions have seen an estimated 10 to 15 per cent rise in major cities. The World Health Organization estimates that 175,000 people die from heat-related causes annually in Europe, with the region accounting for 36 per cent of global heat-related deaths. During a less intense European heatwave in 2024, a study found more than 2,300 deaths in 12 cities alone, with two-thirds attributed to climate change. In summer 2022, over 60,000 people died due to heat in Europe. Tragically, 40 people reportedly died in drowning accidents in France while trying to escape the heat.
Italy’s health ministry issued a red alert for the heatwave in 18 cities including Milan, Rome, Turin, Venice, Genoa, Florence and Bologna for Saturday and Sunday, with temperatures expected to climb as high as 39C in some areas. Almost half of Europe’s 850 largest cities are experiencing their worst-ever heat stress – a combination of temperature and humidity that makes sweating less effective for cooling the body.
Infrastructure has buckled under the strain. In Germany, the national rail operator Deutsche Bahn gave customers the option of cancelling long-distance travel bookings into early next week without charge, citing particular strain on infrastructure from sun exposure and additional risk to signals, tracks and overhead wires from thunderstorms and wildfires. Near Hamburg, the main traffic lane on a section of the A7 autobahn – one of Germany’s busiest motorways – was closed after heat caused the asphalt to split. Authorities urged people to save water, and André Berghegger, the CEO of the German Association of Towns and Municipalities, said local authorities should only impose bans if voluntary cooperation fails. In France, temperatures above 40C disrupted rail travel and power generation, prompted alcohol bans and school suspensions, and postponed outdoor events. Public service providers have sought to reduce traffic because of the risk of buckling roads and swelling train tracks.
In the Balkan region, a heatwave in June led to major power cuts. Serbia and Croatia experienced record electricity demand in July as temperatures reached 43C. France’s nuclear power plants have faced capacity curtailments due to high river water temperatures used for cooling, and thermal power plants are also affected by cooling issues and low river levels. Demand for electric fans has shot up, and Asian air-conditioning manufacturers have reported a European sales boom. Most of the housing stock in northern Europe is built to keep heat in rather than withstand it.
Agriculture has suffered heavily. In Hungary, tens of thousands of hectares of maize, sunflower and sugar beet crops have been destroyed, with maize losses alone expected to exceed €600 million. Some areas have seen losses of up to 90 per cent for crops such as maize and sunflowers. Potatoes are particularly sensitive, with temperatures above 30C significantly impacting yields.
Wildfires are also on the rise. Reports of wildfires in France are up compared with the same period last year as a result of the heatwave, officials said. Across the European Union, the 2024 wildfire season saw a total burnt area of 419,298 hectares – lower than 2023 but above the 17-year average. Portugal experienced its worst year for forest fires since 2017, with 147,461 hectares burned. Ukraine saw nearly one million hectares burned, largely along conflict frontlines. Fire danger levels were average to slightly above average in summer 2024, with the highest values in September due to dry conditions and strong winds, particularly in Portugal and Spain. Southeastern Europe also experienced above-average fire danger in June and August due to extreme temperatures.
Cultural landmarks have had to close, and outdoor events have been postponed or curtailed. The start of the Milan Pride march was delayed to avoid the worst of the heat, and the Ironman European Championship long-distance triathlon in Frankfurt shortened the cycling and running courses because of the heat, organisers said. The most extreme heat is forecast to begin fading at the weekend, with heavy thunderstorms expected on Sunday.
The role of climate change and the Omega block
Scientists from World Weather Attribution have stated that this heatwave would have been “virtually impossible” without human-induced climate change. Their analysis indicates that the heatwave is the most severe ever recorded in the region, driven by rising temperatures that are outstripping the rate of global warming. Night-time temperatures during this heatwave are about 100 times more likely than they were two decades ago. A similar heatwave in June would have been about 3.5C cooler during the day in 1976 and about 2C cooler in 2003 due to global warming. Europe is warming at a rate twice as fast as the global average, and 2024 has been confirmed as the warmest year on record for the continent. The UN’s climate chief attributed the heatwave to the world’s “addiction to burning coal, oil and gas”.
The heatwave has pushed temperatures up to 18C above their seasonal average, according to the Reuters Climate Monitor, driven by a phenomenon known as an Omega block. This weather pattern involves a stalled, Ω-shaped wind pattern in which a bulge of warm high pressure becomes trapped between two cooler low-pressure systems. The block prevents ventilation, leading to a build-up of heat and hot, dry conditions. Because it suppresses cloud formation, the skies remain clear and sunny, which further intensifies surface temperatures. Omega blocks can last from three to ten days, but sometimes persist for weeks. In this instance, the block has trapped hot, dry air from North Africa over large parts of Europe. The result is a bulging ball of hot air that sits over regions for extended periods, with cooler air on its fringes. One in five workers in the EU is exposed to high temperatures at work, with agriculture and construction sectors particularly vulnerable. Extreme weather events have cost Europe over €145 billion in economic damages between 2012 and 2022, with climate-related losses growing by approximately 2 per cent annually. The UK’s Climate Change Committee has warned that the country’s infrastructure is “built for a climate that no longer exists” and requires urgent improvement. Deutsche Bahn is investing in climate-resilient station environments and testing technologies to protect sensitive equipment from heat. Portugal has shifted its spending priorities towards fire prevention.
