At least 35,000 excess deaths in Europe in the summer of back-to-back heatwaves

Provisional data from national surveillance systems indicate that the consecutive heatwaves of summer 2026 in Europe have produced at least 35,000 excess deaths. In Germany, France and Spain alone, excess mortality already exceeds 25,000 deaths according to provisional national figures.

The news currently stems from a single journalistic source (The Irish Times, reporting provisional data from national health agencies); no independent confirmation is available. The individual figures cited are attributed to identified health institutions, and it is on those attributions that this piece rests.

The numbers, country by country

Country / system	Estimate	Period
Spain, MoMo system (Carlos III Health Institute)	4,947 heat-attributable deaths	May – last week
England, UK Health Security Agency	2,877 heat-associated deaths	May and June heatwaves
Belgium	1,222 additional deaths, +39% mortality	June 18–29
Netherlands	at least 900 additional deaths	June 22 – July 5
Poland, rapid modelling cited by the European Commission	1,070 additional deaths	late-June heatwave
Switzerland, health authorities	220 excess deaths	same week

The Spanish figure offers the clearest point of comparison: the 4,947 attributable deaths exceed the 4,520 recorded in 2022, which had until now been the record year detected by the MoMo system.

Why these numbers do not simply add up

National systems use different methodologies, and this is a limitation acknowledged by the very bodies that produce them. Some calculate excess mortality against a statistical baseline, others estimate heat-attributable deaths using models; some figures cover the entire season, others single heatwaves lasting a few days; some concern an entire country, others only part of it — the British figure cited refers to England.

There is also a clinical reason why the count is indirect: heat rarely appears as a direct cause of death, and instead acts by aggravating pre-existing cardiovascular or respiratory conditions. This is why heat-related mortality is measured by comparing observed deaths with expected ones, rather than by counting death certificates.

It should also be noted that the Polish figure comes from a rapid modelling study cited by the European Commission: rapid estimates are early-warning tools, produced before demographic data have been consolidated, and are subject to revision. All the values reported here are provisional and may be revised, in either direction, once the national series are finalized.

What we don’t know

We do not know the breakdown of the German and French figures, which together with Spain make up the largest part of the aggregate. We do not know the methodology used to compile the overall figure of 35,000, nor the exact geographic scope it refers to. Breakdowns by age, region or concurrent cause are not available.

This newspaper does not publish health-related behavioural guidance: for recommendations, those issued by national health authorities apply, as they are the bodies entitled to issue them. The next verifiable element will be the consolidation of national mortality series, which will make it possible to compare summer 2026 with 2022 on a consistent basis rather than through provisional estimates.

Source: The Irish Times, reporting provisional data from the Carlos III Institute–MoMo, the UK Health Security Agency, and Belgian, Dutch and Swiss authorities.