Heat that hit Europe exceptionally early and hard this year appears to have led to a spike in deaths, with well over 10,000 more people dying at the height of the heat wave than would normally have been expected, according to figures that are still emerging across the continent.

Measures of what researchers call “excess mortality” — the difference between the normally expected number of deaths and the actual number — spiked in late June, when parts of Europe experienced record temperatures. Experts caution that it takes a while for a full picture to emerge, and that many heat-related deaths will never formally be recorded as such. For example, a heart attack, which can be triggered by extreme heat exposure, especially in people who are older or have underlying health issues, may be listed on a death certificate simply as a heart attack.

It’s an alarming start to the summer. Several heat waves have killed thousands of people in the past few years in Europe. Still, 2003 stands as the deadliest year in Europe for heat, with about 70,000 deaths. The frequency and intensity of heat waves are supercharged by climate change, which comes from the burning of fuels like coal, oil and gas.

The EuroMOMO mortality monitoring hub, which receives data from two dozen countries, gave an estimate of 14,260 for excess mortality from all causes in the week ending June 28, more than 12,000 of those deaths being among people age 65 and older. That’s out of a total 84,583 deaths that week. Figures in the preceding and following weeks were far lower.

Lasse Vestergaard of Denmark’s Statens Serum Institut, which coordinates EuroMOMO, said that “we attribute this to the heat wave affecting quite a lot of countries in Europe, and we do that because there is no other obvious explanation that could explain such a high excess mortality happening at the moment.”

Such a high excess in a single week is “highly unusual,” he added. EuroMOMO doesn’t give absolute numbers for individual countries, but found the highest rates of excess in France, Belgium and Germany.

Nations that bore the brunt of the heat have issued their own estimates — which don’t always follow the same methodology or timelines. Here is a snapshot of heat-related deaths being reported by various countries.

Germany’s disease control center, the Robert Koch Institute, directly attributed 6,830 deaths to heat this year through early July, 6,470 of them among people 65 and older. Temperatures in Germany late last month hit their highest levels since records began, peaking with a measurement of 41.7 degrees Celsius (107.06 Fahrenheit) on June 28, according to the German Weather Service.

Britain’s Met Office, the national weather agency, said that 2,700 people are believed to have died from heat-related causes during heat waves in England and Wales in May and June. Of those deaths, it says that about 550 occurred in late May and about 2,200 in late June. This year brought national heat records for May of 35.1 Celsius (95.18 Fahrenheit) and for June of more than 37 Celsius (98.6 Fahrenheit).

France’s public health authority said there were at least 2,000 more deaths in the week of June 22-28 than the previous week, when temperatures were already climbing. France recorded its hottest-ever days on June 24 and 25, when the Meteo France weather service said the national thermal indicator — an average of daily temperatures measured at 30 weather stations — hit 30 Celsius (86 Fahrenheit). More than 40% of France saw peak temperatures of above 40 Celsius (104 Fahrenheit).

An estimated 937 deaths in Spain in June were attributed to excess heat, according to the Carlos III Health Institute, an official Spanish monitoring agency. Last month was Spain’s second-hottest June on record, with temperatures 3.2 Celsius (5.8 Fahrenheit) above the monthly normal average, according to the AEMET weather agency. A five-day heat wave saw temperatures regularly surpass 40 Celsius (104 Fahrenheit), AEMET said.

There were 1,747 deaths above what would usually be expected during the heat wave that ran from June 18 to July 1, according to Sciensano, Belgium’s public health institute. It said that “a certain excess mortality is expected during heat waves, as during waves of cold weather and flu epidemics. Nevertheless, the heatwave of June 2026 is distinguished by its exceptional breadth.”

At the peak of the heat wave, there was a measurement of 35.5 Celsius (95.9 Fahrenheit) on June 26, the IRM weather institute said.

An initial estimate of excess death figures from the June heat wave found that the Netherlands had 480 more deaths than expected, according to the public health service. Increased mortality was particularly notable in eastern and southern areas, where the temperatures were the highest.

The country saw its highest temperature ever for June, with the Dutch weather service registering 36.8 degrees Celsius (98.24 Fahrenheit). That’s more than a degree Celsius (1.8F) higher than the previous record, set in 1947.

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