The heat wave at the end of June set new meteorological records in Germany. According to the German Meteorological Service (DWD), Coschen in Brandenburg reached 41.7 degrees Celsius on 28 June, a new national record. The previous mark of 41.2 degrees from July 2019 (Duisburg-Baerl and Tönisvorst) had in fact already fallen several times within three days, including 41.3 degrees in Saarbrücken-Burbach.
For health, though, the lack of cooling at night mattered more. In Kubschütz (Saxony), the temperature did not drop below 29.4 degrees Celsius in the night into 28 June, the warmest night ever recorded in Germany. The previous record of 27.2 degrees from 2003 was exceeded by more than two degrees.
For the health system and for occupational safety, this is turning into a structural problem. The WHO reports more than 1,300 additional heat-related deaths across Europe since 21 June. France alone recorded around 1,140 excess deaths, Spain at least 327 suspected heat deaths. For comparison, Germany's Robert Koch Institute estimates roughly 3,000 heat-related deaths per year in recent summers, which makes heat the deadliest weather-related hazard in Europe.
Neither social nor built infrastructure is prepared for heat this frequent and this intense.
Vulnerable Groups at the Centre of Climate Adaptation
Medical research shows that extreme heat hits some population groups much harder than others.
Older and chronically ill people: The human body regulates heat through the cardiovascular system. During a run of tropical nights (minimum temperatures above 20 degrees Celsius), the body never gets to recover, and rates of heart attacks, strokes and partial kidney failure rise to a statistically significant degree.
Outdoor workers: People working in construction, logistics and agriculture are exposed to direct sunlight and high ambient temperatures. Without adjusted working hours and ways to cool down, they risk acute dehydration and heat stroke. Germany's workplace regulation ASR A3.5 requires effective measures above 30 degrees indoor temperature; above 35 degrees, a room without technical protection counts as unsuitable for work. Comparably binding thresholds for outdoor work are still largely missing.
Urban populations: Due to the urban heat island effect, sealed inner cities heat up considerably more than the surrounding countryside; on calm nights the difference can reach several degrees. Hospitals, care homes and residential buildings in Germany were historically built to keep heat in rather than out, so the risk in these microclimates rises sharply.
The Statistical Outlook to 2030
The current report by the World Meteorological Organization (WMO), the Global Annual to Decadal Climate Update 2026-2035, makes clear that these are not one-off events. The WMO predicts with a probability of 91 percent that the global mean temperature will exceed the mark of 1.5 degrees Celsius above pre-industrial levels in at least one year by 2030. The probability of a new global annual temperature record is 86 percent, and there is a 75 percent chance that even the five-year mean for 2026-2030 will exceed the 1.5-degree mark.
Research also shows that the extreme scenario of completely unchecked CO₂ growth (RCP8.5) has become unlikely, thanks to the global expansion of renewable energy. Still, current policies point to around 2.8 degrees Celsius of warming by the end of the century, according to the UN Emissions Gap Report, so climate adaptation remains necessary.
From Reaction to Prevention
The focus therefore has to move away from purely reactive measures. What is needed are municipal heat action plans drawn up in advance, structural retrofits of healthcare facilities, and occupational safety rules adapted to the changed climate.
France shows that this works. After the 2003 heat summer, with an estimated 70,000 deaths across Europe, the country introduced its national "Plan Canicule", which has warning levels, registries for at-risk people living alone, and clear responsibilities. In Germany, by contrast, only a fraction of municipalities have adopted a heat action plan so far. The June heat wave is a reminder that climate adaptation is already overdue.