Cologne sits on the Rhine river in western Germany and receives around 800 mm (about 31 inches) of rain a year, spread fairly evenly across the seasons. The Rhine has a history of significant flooding during periods of sustained heavy rain across its wider catchment, and the city has adapted with flood walls and barriers along its historic riverside. More localized summer thunderstorms, sometimes severe, are a separate and more sudden hazard, capable of flash flooding streets in a way that has little to do with the river’s water level. Because these two flood risks work on very different timescales, radar is specifically useful for the fast-developing summer storm side of the equation. Germany’s DWD operates the national radar network.
Learn more: How Does Rain Radar Work? · Open the full Rain Map