During the late evening hours, temperatures in urban areas often remain noticeably higher than in surrounding rural environments. This phenomenon is known as the Urban Heat Island (UHI) effect. On Friday, May 1st – one of the first significantly warm days of the year – the city-wide measurement network of the Data2Resilience project provided illustrative insights into temperature variations across Dortmund.

Measurements taken at 11:00 p.m. revealed considerable differences within the urban area. While nearly 20 °C were recorded at the central Brückstraße station, temperatures at less densely built-up locations such as Scharnhorst or near-natural areas along the Emscher were significantly lower.

These differences clearly demonstrate the Urban Heat Island effect. In densely built and sealed areas, heat and stored energy persist longer, whereas greener or less compact zones cool down more quickly.

Such localized temperature analyses provide an important basis for climate-adapted urban development. The goal of the Data2Resilience project is to systematically collect, process, and make urban climate data usable for municipal adaptation strategies.