Kassel is burning: heat wave hits the city with record temperatures!

Kassel is burning: heat wave hits the city with record temperatures!

On Wednesday, July 3, 2025, Kassel experienced the peak of a severe heat wave. While the maximum temperatures in Hesse on Tuesday were close to 40 degrees, the record high of 36.8 degrees from 1880 remained unmatched. In Kassel, 35.1 degrees were measured on Tuesday, which is the hottest temperature of the year. The German Weather Service (DWD) warned of “extreme heat” and the associated dangers until the evening hours.

This extreme heat wave has already had its first serious effects. Roads burst on the A5 motorway and numerous emergency medical calls were recorded due to dehydration and heat stroke. The situation at the bathing lakes is also critical: high temperatures and increased nutrient levels promote the possible development of blue-green algae, which poses additional health risks to bathers. The Hessian State Office for Nature Conservation, Environment and Geology (HLNUG) recommends paying attention to the visibility of the lake bottom and avoiding swimming if the water is cloudy. There are currently no known occurrences of blue-green algae, but the warning remains in effect, especially as water temperatures may continue to rise reported.

The consequences of climate change

The background to the current heat wave is climate change, which not only leads to more frequent and intense heat waves, but also has far-reaching health consequences. According to the World Health Organization (WHO), climate change is classified as one of the greatest health threats to humanity. Vulnerable groups such as older people, newborns and pregnant women are particularly affected. Heat-related deaths are increasing, and in the summer of 2023, for example, over 47,000 people died in Europe as a result of extreme heat, and several thousand died in Germany describes the situation.

The situation could become even more complicated due to the further spread of heat-loving animal species. For example, the Asian tiger mosquito is spreading in Germany and can transmit tropical diseases such as dengue and Zika fever. This also poses a serious danger in local climatic conditions, especially if temperatures continue to rise. The data shows a worrying rise in temperatures: 2024 was the warmest year on record, with a further rise of 1.55 degrees Celsius above pre-industrial levels.

Outlook for the coming days

However, the heat wave in Hesse will take a short break in the coming days. Rainfall and thunderstorms are forecast on Thursday, moving eastward. From Friday the maximum temperatures will settle around the 30 degree mark, with a maximum of 29 degrees on Friday and up to 31 degrees on Saturday. On Sunday, temperatures are expected to cool down to between 24 and 27 degrees, which could bring welcome relief for the population. The overview of the coming days shows a clear trend reversal:

It remains to be seen what long-term effects this heat wave will have on population health. Climate change, it seems, will remain an explosive issue in the future that requires urgent action.