An unusually early and intense heat wave across Europe in late June appears to have caused a significant surge in deaths, with preliminary figures indicating over 10,000 more fatalities than typically expected for that period. Experts caution that the full impact may take time to be determined, as heat-related deaths are often not formally attributed to heat exposure on death certificates.
Excess mortality, a measure of deaths from all causes above the normal average, saw a sharp increase during the week ending June 28. Data from EuroMOMO, a mortality monitoring hub covering two dozen European countries, estimated 14,260 excess deaths during that week. More than 12,000 of these occurred among individuals aged 65 and older, out of a total of 84,583 deaths recorded that week. Figures in the weeks preceding and following this peak were considerably lower.
Lasse Vestergaard of Denmark's Statens Serum Institut, which coordinates EuroMOMO, stated that this excess mortality is attributed to the widespread heat wave, as no other clear explanation is apparent for such a high spike. He described the surge as "highly unusual."
While EuroMOMO does not provide country-specific absolute numbers, it identified France, Belgium, and Germany as experiencing the highest rates of excess mortality. Individual nations have released their own estimates, using varying methodologies and timelines.
Germany's Robert Koch Institute directly linked 6,830 deaths to heat through early July, with 6,470 of those among people aged 65 and older. Germany recorded its highest temperatures since record-keeping began on June 28, reaching 41.7 degrees Celsius (107.06 Fahrenheit).
In Britain, the Met Office reported an estimated 2,700 heat-related deaths across England and Wales during heat waves in May and June. Approximately 550 of these deaths occurred in late May, and 2,200 in late June. Both May and June saw national heat records, with temperatures exceeding 35.1 Celsius (95.18 Fahrenheit) and 37 Celsius (98.6 Fahrenheit), respectively.
France's public health authority reported at least 2,000 additional deaths in the week of June 22-28 compared to the preceding week. The country experienced its hottest days on June 24 and 25, with national average temperatures reaching 30 Celsius (86 Fahrenheit) and over 40% of the country exceeding 40 Celsius (104 Fahrenheit).
Spain's Carlos III Health Institute estimated 937 excess deaths in June due to heat. The month was the second hottest on record for Spain, with temperatures averaging 3.2 degrees Celsius (5.8 Fahrenheit) above normal. A five-day heat wave saw temperatures regularly surpass 40 Celsius (104 Fahrenheit).
Belgium's public health institute, Sciensano, recorded 1,747 deaths above expected levels between June 18 and July 1. The institute noted that while some excess mortality is expected during heat waves, this particular event was distinguished by its "exceptional breadth."
The Netherlands registered an initial estimate of 480 excess deaths during the June heat wave, with increased mortality concentrated in the hotter eastern and southern regions. The country recorded its highest June temperature on record at 36.8 degrees Celsius (98.24 Fahrenheit), surpassing the previous record from 1947.
These figures highlight the increasing frequency and intensity of heat waves, which climate scientists link to climate change driven by the burning of fossil fuels. The summer of 2003 remains the deadliest on record for heat in Europe, with approximately 70,000 fatalities.