The German state of North Rhine-Westphalia - particularly the Ruhr Valley and Münsterland - was hardest hit, with heavy damage to rooftops and windows. A meteorologist for German weather service DWD said up to 40 litres of rain per hour - about half a month's worth of precipitation - fell in certain places.
In Essen, branches and fallen trees blocked roads and forced the city to close two street car lines to clear detritus from tracks and electrical lines.
Meanwhile, the state of Brandenburg had fierce thunder and lightning storms throughout the night, causing a power outage in Cottbus.
A lightning strike is thought to have ignited a fire at a textile factory in Ramstein-Miesenbach, causing several hundred thousand euros of damage, police said Monday. No one was injured.
Before the storm hit late on Sunday evening, Germany enjoyed one of the hottest days of the summer, with temperatures rising well above 30 degrees Celsius in many cities, the DWD reported Monday. The medieval Bavarian town of Regensburg came out on top, reaching 35 degrees Celsius, DWD meteorologist Dothea Paetzold said.
But as a cold front from the northwest hit the the hot air, Paetzold said northern Germany suffered golf ball-sized hail, heavy rain and wind gusts of up to 100 kilometres per hour. Southern Germany can expect inclement weather for the next few days as the cold front lingers, she said.