On average, heatstrokes, sunburns, and other illnesses caused by heat or strong sunlight have resulted in nearly 1,400 hospitalizations between 2004 and 2024. However, according to the Federal Statistical Office, assigning heat as the direct cause of death is rare, averaging only 21 cases across the same 20-year period. Despite this, high temperatures significantly increase overall mortality, often because the combination of heat exposure and pre-existing health conditions raises the risk of death. Mortality rates have demonstrably risen during weeks characterized by heatwaves; in several instances, the death toll exceeded previous year comparisons by more than 20%, most recently observed in a July week in 2022.
Estimates from the Robert Koch Institute (RKI) consistently show that heat periods in Germany lead to higher death rates. The RKI combines death statistics from the Federal Statistical Office with temperature measurements from the German Weather Service to track this trend. During the period between 2004 and 2024, the RKI reported the highest estimated heat-related mortality in 2018, with approximately 8,500 deaths attributed to heat. The second-highest year was 2006, with an estimated 7,700 deaths.
High rates of heat-related hospitalization and fatalities frequently occur in years with many “heat days,” defined as days reaching 30 degrees Celsius or more. For example, in 2015, the number of hospitalizations due to heat and sunlight damage reached just over 2,300 cases, which was 72 percent higher than the 2004-2024 average. Furthermore, 60 deaths in that year were attributed to heat or sun, nearly three times the average observed during the 2004-2024 period. The German Weather Service noted that 2015 was above average for heat days.
The year 2018 featured the highest number of heat days between 2004 and 2024, totaling 20.4 days. During 2018, hospitalizations for heat and sun-related damage numbered 1,600, which was 18 percent above the average. Additionally, statistics showed that the number of deaths directly listed on the death certificate as being caused by heat or sunlight was 28, a figure slightly above the overall average.
