Heat in Cities  Heating Up: German Cities in the Climate Crisis

Is Germany prepared for the heat? Yes and no. Here's how cities are making plans to combat the heat, despite being confronted with a wide variety of conditions. We take a look at Stuttgart, Essen, Kassel and Leipzig.

The ground glows and the air shimmers over the tarmac. Sweat sticks to the back of your neck. A siesta behind darkened windows or a dip in the cool water would be a good idea. But not a walk through the city centre, where shaded areas are as rare as oases in the desert. While our grandparents had to travel to southern Europe for temperatures above 30 degrees, we can now enjoy them at home. Germany is experiencing rising temperatures due to the climate crisis.

According to a report by World Weather Attribution, Germany experienced 50 hot days between May 2024 and May 2025, 24 of which were made more likely by climate change. And heat has consequences: People become more irritable, domestic violence increases and concentration decreases. Heat can also be life-threatening for older people, those who are unwell, and children. A study by the Umweltbundesamt found that around 3,000 people died in Germany in 2024 due to high temperatures.

Cities are particularly affected by heat. This is due to urban heat islands, which can increase air temperatures by more than 5°C compared to rural areas. The causes are manifold. For instance, asphalt and concrete absorb heat during the day and release it into the environment at night. Further, cities often have limited green spaces that can absorb the sun's rays.

In Germany, 71 per cent of people live in cities. Although heat islands can be an issue anywhere, cities have to contend with very different conditions. Stuttgart, Essen, Kassel and Leipzig are examples of how geographical differences and the after-effects of German history can affect temperatures.

Stuttgart: City in the Basin

Stuttgart is one of the warmest cities in Germany. Centuries ago, the mild climate prompted the Romans to cultivate wine grapes around the basin where the city is located. However, climate change is making temperatures rise. Ironically, the city is expected to have a climate similar to that of Rome in 50 years' time. As early as 2049, climate change could bring Stuttgart up to 70 hot days, i.e. days with temperatures above 30°C.

The state capital of Baden-Württemberg must therefore take countermeasures — and is trying to do so. The city council adopted a climate protection concept as early as 1997. Over the years, plans for heat protection have been added, such as measures to unseal areas: concrete and asphalt are to be removed and replaced by green spaces. According to a Correctiv analysis, Stuttgart gained one square kilometre of green space between 2018 and 2024, but also lost one square kilometre to sealing. Compared to Leipzig (+6 square kilometres of sealing) and Hamburg (+14 square kilometres of sealing), this is a relatively good balance. In particular, Stuttgart's heavily built-up city centre has been unsealed, whereas the more affluent suburbs have been sealed.

Study results from US cities reveal contrasting conditions: Poorer communities tend to live in densely populated neighbourhoods with no green spaces, whereas wealthy neighbourhoods tend to live in areas with green spaces. Therefore, Stuttgart, a city often associated with industry and cars, comes as a surprise.

Essen: Social Inequality

In comparison to Stuttgart, Essen is marked by a pronounced rich-poor divide across its various neighbourhoods. The city centre and the northern districts are densely populated and therefore hotter than the wealthier southern districts. Within the city, the number of hot nights with temperatures above 20°C varies from two to eleven days. This situation is exacerbated by economic factors. For example, whether or not you can afford air conditioning.

However, the north of Essen is home to the flagship project "Grüne Mitte" (central green area) — a modern district built on a former freight depot. The vast station site has been transformed into a loosely built-up neighbourhood featuring green roofs, a four-hectare park, and long water basins filled with rainwater almost year-round. This "blue" infrastructure is particularly valuable. Green spaces are up to 0.94°C cooler than the surrounding urban areas, and bodies of water have an even greater cooling potential of up to 2.5°C.

However, planting trees or creating bodies of water is not always easy. In open spaces, new green areas often have to compete with residential and commercial developments. In densely built-up neighbourhoods, it is often impossible to plant trees due to cables, roads, and sewage pipes. Furthermore, to measurably cool places, it is not enough to plant individual façades; a comprehensive plan is needed. According to the city of Essen, this is what the "Masterplan Stadtgrün" aims to achieve. It will be interesting to see how Essen develops over the next few years.

Kassel - The Car-Friendly City

Lined up side by side, half-timbered houses once defined the city of Kassel. Then, on 22 October 1943, 97 per cent of the medieval old town was destroyed in bombing raids. After the Second World War, the city was left in ruins, prompting a pivotal decision: Should it be rebuilt according to the historical model or remodelled in the spirit of modernism?

The latter was chosen, and Kassel was transformed into a "car-friendly city": traffic planners ensured an uninterrupted driving experience for motorists and directed pedestrians to use subways at intersections. There were also to be pedestrian zones and designated green spaces. The idea was to "functionally separate" living, working, recreation and transport.

These post-war plans still characterise the city today. Wide road corridors cause noise and air pollution and contribute to the formation of heat islands through soil sealing. Although there are many gardens and parks in Kassel, they are not evenly distributed. In some neighbourhoods, green spaces for recreation are scarce. Recognising this, the city is trying to address the issue with the "Smart City Kassel" initiative. Further, climate-adapted tree species are being distributed.

However, it remains to be seen whether car-friendly Kassel can be quickly transformed into a climate-friendly city.

Leipzig - The Growing City

According to a Heat Check study carried out by Deutsche Umwelthilfe (DUH) in 2024, Leipzig was one of the cities to receive a "green card" for land sealing and green spaces, thanks to the alluvial forest running through its centre. However, when the distribution of residents is considered, as DUH did in a recently published Heat Check 2.0, it becomes clear that most Leipzig residents live in areas moderately to severely affected by heat. According to a survey, the majority of Leipzig's population feels that the heat in the city is more intense and supports more protective measures.

This is a recurring problem: a city is described as green, yet it heats up in summer. Similar to Kassel, Leipzig also has large parks. However, the trees and green spaces are too concentrated to have a positive effect on all neighbourhoods. For this reason, it is important to take a closer look at the statistics.

Leipzig has been one of the fastest-growing cities in Germany for many years. The city is experiencing an influx of both companies and people, creating a need for more residential and commercial areas. Adapting to the heat is thus becoming a challenge, as green spaces are competing with new construction projects. According to Correctiv, Leipzig's proportion of concrete and asphalt increased by six square kilometres between 2018 and 2024.

So, what is Leipzig doing? For instance, the city council has adopted a heat action plan that includes a heat warning app, information campaigns on how to behave safely in hot weather, an expansion of public drinking water supplies and a map showing cool places. Additionally, a strategy is being developed with the aim of achieving net-zero sealing by 2030. This means that the amount of land unsealed should equal the amount of land sealed.

However, Leipzig is still a long way from achieving net-zero sealing. Moreover, the city is expected to continue growing. A challenge in times of global warming.

June 2025