An exceptionally intense and early summer heat wave that swept across Europe in late June has been linked to more than 10,000 excess deaths, according to newly emerging mortality data, raising fresh concerns over the growing human toll of climate-driven extreme weather.

Health experts and meteorological agencies across the continent say the prolonged period of record-breaking temperatures caused a sharp rise in mortality, particularly among older adults and people with pre-existing health conditions. Researchers warn that the true death toll is likely to be significantly higher because many heat-related fatalities are not officially recorded as being caused by extreme temperatures.

Excess mortality spikes across Europe

The European Mortality Monitoring Project (EuroMOMO) reported an estimated 14,260 excess deaths from all causes during the week ending June 28, one of the highest weekly mortality increases recorded in recent years. More than 12,000 of those deaths occurred among people aged 65 and older, highlighting the disproportionate impact of extreme heat on vulnerable populations.

Lasse Vestergaard of Denmark's Statens Serum Institut, which coordinates EuroMOMO, said the widespread heat wave remains the most plausible explanation for the sudden spike in deaths.

"We attribute this to the heat wave affecting quite a lot of countries in Europe because there is no other obvious explanation that could explain such a high excess mortality happening at the moment," Vestergaard said.

According to EuroMOMO, the highest levels of excess mortality were observed in France, Belgium and Germany.

Germany reports highest number of heat-related deaths

Germany has recorded the largest national toll so far.

The Robert Koch Institute (RKI) said 6,830 people died from heat-related causes through early July, including 6,470 people aged 65 or older.

The country experienced unprecedented temperatures during the final days of June, with the German Weather Service (DWD) registering 41.7 degrees Celsius (107.1°F) on June 28, among the highest temperatures ever measured in Germany.

United Kingdom sees thousands of deaths

Britain's Met Office estimated that approximately 2,700 people died from heat-related causes during heat waves affecting England and Wales in May and June.

Officials estimate around 550 deaths occurred during the late May heat event, while another 2,200 deaths were linked to the more intense heat wave in late June.

The United Kingdom also recorded its hottest May on record, followed by one of its hottest Junes, with temperatures exceeding 37 degrees Celsius.

France experiences historic temperatures

France also reported a significant increase in mortality.

The country's public health agency said at least 2,000 additional deaths occurred during the week of June 22-28 compared with the previous week.

France experienced its hottest days ever recorded on June 24 and 25, when the national thermal indicator reached 30 degrees Celsius, while more than 40 percent of the country recorded temperatures above 40 degrees Celsius (104°F).

Authorities activated nationwide heat emergency measures, opening cooling centers, extending hospital preparedness plans and issuing repeated health warnings to residents.

Spain records nearly 1,000 heat-related deaths

Spain's Carlos III Health Institute estimated that 937 deaths in June were attributable to extreme heat.

The country's weather agency AEMET reported that June was Spain's second-hottest on record, with average temperatures 3.2 degrees Celsius above normal.

Several regions experienced temperatures exceeding 40 degrees Celsius for five consecutive days, placing additional strain on healthcare services and emergency responders.

Belgium and the Netherlands also affected

Belgium's public health institute Sciensano estimated 1,747 excess deaths during the heat wave between June 18 and July 1.

Officials described the event as exceptional due to both its geographical extent and sustained intensity. Belgium recorded temperatures of 35.5 degrees Celsius during the peak of the heat wave.

Meanwhile, the Netherlands reported an estimated 480 excess deaths, with the highest mortality concentrated in the eastern and southern parts of the country where temperatures were most extreme.

The Dutch weather service also confirmed a new national June temperature record of 36.8 degrees Celsius, surpassing a record that had stood since 1947.

Climate change increasing frequency of deadly heat waves

Climate scientists say Europe is warming faster than any other continent, making extreme heat events more frequent, more intense and longer-lasting.

The Copernicus Climate Change Service reported that June 2026 ranked among Europe's hottest Junes ever observed, with persistent "heat domes" trapping hot air over much of western and central Europe for extended periods. Researchers say human-induced climate change has significantly increased the likelihood of such prolonged extreme heat episodes.

The World Health Organization (WHO) has repeatedly warned that heat is becoming one of Europe's deadliest weather-related hazards. Health officials stress that older adults, children, outdoor workers, and individuals with cardiovascular or respiratory illnesses remain particularly vulnerable during prolonged periods of extreme heat.

Experts also note that official heat-related death statistics often underestimate the true impact because many fatalities are ultimately attributed to conditions such as heart attacks, strokes or respiratory failure that are triggered or worsened by extreme temperatures.

Public health authorities across Europe are urging governments to strengthen heat adaptation strategies, expand early warning systems, improve urban cooling infrastructure and better protect vulnerable populations as climate change continues to intensify summer heat waves across the continent. (ILKHA)