Europe sweats through its hottest June on record

The last full week of June broke the European temperature record the way the week before it broke the previous one. Germany measured 41.7°C on 28 June, its highest figure on record, on the third consecutive day of new national highs. In France the 24-hour national mean reached 30°C on 24 and 25 June, an intensity Météo-France said had not been seen since 1947. London Underground carriages approached 40°C and more than a thousand English schools either closed or cut their hours. French schools did the same on a larger scale; the education ministry counted about 13,500 establishments running under special arrangements. In Germany trams stopped where the rails buckled and the railway operator urged passengers to postpone travel, while four French nuclear reactors throttled back or shut because the rivers used for cooling were running too warm, cutting more than four gigawatts from the grid.

The immediate cause was a heat dome. A strong high-pressure system sat over western Europe, trapping hot air at ground level while an unusually warm Mediterranean pumped more heat into the atmosphere. That mechanism explains why the temperatures reached where they did; it does not explain why they keep reaching further each decade. Copernicus, the EU’s climate monitoring service, has confirmed that June 2026 was the hottest June on record for western Europe, 3.05°C above the 1991-2020 average. Europe warms at roughly twice the global rate. A heatwave of this intensity, in this location, is what a raised baseline looks like.

The human cost will be the slowest part of the story to arrive. Excess-death statistics lag the weather by weeks, and the first official numbers are only beginning to appear; the World Health Organization said on 28 June that more than 1,300 heat-related excess deaths had been recorded in Europe since 21 June, and that total will rise as national health agencies finish their counts. The victims are overwhelmingly the elderly, the people who cannot move their routines, who live in flats without cooling and whose bodies have the least margin for a week of nights at 25°C. Heat kills quietly, in numbers that rarely make a single headline.

The economic damage is more visible and more telling. This heatwave did not close a few schools; it closed thirteen thousand of them in one country, derailed rail services in another and forced part of France’s nuclear fleet off line at the moment demand for cooling was highest. Hospitals in southern European cities reported emergency departments at capacity. The losses are counted in the same currencies as any other supply shock, except that they arrive every summer now, and each summer is hotter than the last. A country can build its railways for 30°C or for 42°C, but it cannot build them for both at once, and the gap between the design temperature and the operating temperature is where the disruption comes from.

What happens next depends on whether this summer is treated as a weather event or as a planning assumption. The heat dome will lift, the records will be revised, and the political attention will drift to whatever comes after. The infrastructure that failed was designed for a climate that has moved. European governments have spent two decades adapting their buildings and their grids to floods and storms; the data from this June suggests the next adaptation budget belongs to heat, and that the summer just begun is closer to the new normal than to an exception.

Spain is already issuing its own warnings: the state weather agency forecasts 40-44°C across much of the interior this weekend, and Portugal has red alerts in several districts. The June episode was the first heatwave of the summer, not the last one.