Extreme heat caused nearly 1.500 excess deaths in Germany this summer

A new study has found that extreme heat caused by climate change caused nearly 1.500 excess deaths in Germany during the summer of 2025. 

Climate change caused excess deaths in Germany in summer 2025

Extreme heat attributed to climate change caused 1.477 excess deaths in Germany in summer 2025. The figures come from a new study published by the Grantham Institute and led by scientists at Imperial College London and the London School of Hygiene & Tropical Medicine.

Researchers also studied excess death figures in 127 German cities. They found that there were 219 excess deaths in Berlin between June and August, 66 percent of which can be attributed to climate change.

The researchers considered local relationships between temperature and deaths to understand excess mortality during the hottest months of 2025. They compared these findings to models of a hypothetical scenario in which climate change did not exist. 

June to August 2025 was the fourth warmest summer season on record, 0,9 degrees celsius above the 1990-2020 mean, the study explained. During this period, cities in Germany were on average 2,2 degrees hotter than the 1990-2020 mean temperature.

Large amounts of concrete and asphalt, which trap and hold heat, combined with transportation and energy use that generate even more heat, make cities a health risk in heatwaves. 

Study authors underlined the importance of expanding city green spaces, which are known to “decrease this urban heat island effect and provide crucial cooler spaces that can be lifelines for people in heatwaves, particularly lower socioeconomic groups that live in denser housing and are less likely to have air conditioning”. 

Italian cities saw highest excess deaths caused by climate change

According to the study, excess deaths caused by climate change in European cities were the most prevalent in Italian cities over the past summer. 4.597 excess deaths in Italian cities were attributed to extreme heat caused by climate change.

Spain followed, with 2.841 excess deaths in Spanish cities attributed to human-made extreme heating over the season. Germany came in third place, followed by France (1.444 excess deaths due to extreme heat) and the United Kingdom (1.147 excess deaths).

Overall, epidemiologists attributed 16.500 of the 24.400 heat deaths in European cities between June and August 2025 to extra hot weather caused by greenhouse gases.