Real Estate: 35 Degrees Without Shade? German Cities' Heat Protection Put to the Test

Scorching asphalt, stagnant air: Even in Germany, cities are suffering more than ever from extreme temperatures of 40 degrees or more. In view of rising average temperatures worldwide, people must prepare for a new, more challenging heat environment - and urban landscapes and buildings must also be adapted. "Anyone investing in real estate or managing properties today must consider the future climate resilience of a location more than ever before," says Michael Heigl, who is responsible for the sustainability division at the consulting company Wüest Partner.

It is therefore all the more important for property owners to know where in Germany overheated concrete deserts are located and which cities are doing well. The Handelsblatt has evaluated two recently published studies for this purpose. The Deutsche Umwelthilfe (DUH) examined all 195 German cities with more than 50,000 inhabitants.

The analysis looks at how much area in cities is shaded by trees or tall shrubs. Wüest Partner also created a heat index to determine which cities and districts are particularly hot at high temperatures. The Handelsblatt names the places that are best prepared against heat and shows where there is still room for improvement.

Mannheim region is a laggard. One of the laggards in the DUH study is located in the south-west of the republic. Hardly any city in Germany suffers from extreme temperatures as much as Mannheim. The town is one of the last places in the heat vulnerability index of the German Environmental Aid association, which is made up of the indicators sealing, green space volume, surface temperature and population density.

Mannheim also scores poorly in terms of shading, with an estimated 14.14 percent, according to DUH. For the shading, the organization measures how much of the urban area is covered by tree crowns, i.e., how much soil is shaded by trees. Experts recommend that tree crowns should cover at least 30 percent of the urban area. However, in 2021, the municipal council already adopted a heat action plan.

Practical consequences: 1,000 trees were planted, green islands and facade greening were promoted, and the newly designed station forecourt was laid out with white soil, as this type of surface reflects sunlight better. But even the consultants at Wüest come to a negative conclusion for the entire region. According to their study, conurbations in western and southern Germany are most susceptible to heat stress, particularly in the Rhine-Neckar and Upper Rhine areas.

The five cities with more than 20,000 inhabitants with the highest index values are all located there: Ludwigshafen, Mannheim, Hockenheim, Germersheim and Speyer.

Freiburg im Breisgau is in the middle of the pack. Environmentally friendly, green: Freiburg im Breisgau markets itself as a "Green City." But so far, this only helps to a limited extent to protect against heat. In the important criterion of the proportion of urban area that is planted with shade-providing vegetation, Freiburg is in the red zone with 18.72 percent, according to Environmental Aid.

The heat vulnerability index also shows a red rating. To protect against heat, Freiburg has ordered a climate adaptation strategy that focuses on particularly vulnerable groups and prioritizes the reduction of urban temperatures. The town benefits from a centuries-old achievement: the old town is already cooled by numerous narrow canals, known as Bächle.

There are also water nebulization systems on large squares, whose fine spray mist is intended to lower the outside temperature. However, the heat load does not depend solely on the size of the cities, emphasizes Wüest Partner. What is decisive is an interplay of basic climatic stress, settlement structure and the availability of open spaces, the authors write.

Frankfurt am Main is also in the middle of the pack. The banking city with its many high-rise buildings is unlikely to come to mind spontaneously when asked about plenty of greenery. However, in terms of the shading criterion, which indicates the estimated coverage of the soil by vegetation, Frankfurt achieves 20.58 percent, according to Environmental Aid, and thus lands in the middle of the field.

The heat vulnerability index, on the other hand, is in the red zone. Frankfurt wants to improve. In the future, trees will provide shade more frequently. At the same time, the city is removing asphalt and paving stones to improve the urban climate. In late 2025, the city won the nationwide "Abpflastern" competition with the most removed paving stones per inhabitant.

At the same time, the city is setting up so-called "green rooms" in the city center. These are planted mobile modules that are intended to provide more shade, better air quality and an improved microclimate on sealed squares. However, the costs of the modules are repeatedly discussed critically. Including ancillary costs and value-added tax, the price per piece is around 67,000 euros.

Kiel is a frontrunner. Not the eco-city Freiburg or the green Tübingen are at the top of the DUH list. It is the Schleswig-Holstein state capital Kiel, which, according to evaluations by the German Environmental Aid, belongs to the heat-robust pioneer cities in Germany in 2026. In the Fördestadt, there are comparatively many trees that provide shade.

There are also numerous green spaces that provide cooling through evaporation. In terms of tree shading, Kiel is among the top group in Germany with around 32 percent, according to DUH. The heat vulnerability index is also in the green zone. Generous green and water areas in cities, like mountains and forest regions, have a cooling effect, emphasizes Wüest Partner.

Kiel thus benefits from its geographical location and its urban climate. The proximity to the Baltic Sea not only ensures a more pleasant air humidity but also keeps temperature increases in the city usually within a tolerable range.

Wuppertal is also a frontrunner.