In Lower Saxony, Northeim fire department workers reported rains heavy enough to seep through closed windows and streets under at least 20 centimetres of water. Manhole covers burst several metres into the air from water pressure and city drainage systems couldn't contain the flow of water by 5:30 pm in both Northeim and Hildesheim, police said.
Meanwhile Red Cross workers rescued 32 children from the Rhume River when they were overcome by the unexpected flood waters on a class canoe trip.
"In places, this storm was worse than Kyrill," the fire chief said, referring to the violent storm that hit Germany in January of 2007 that caused extensive damage.
The region near Hannover suffered severe thunderstorms on Thursday night, and police in Burgdorf-Hänigsen reported that canals were beyond capacity, flooding streets and cellars.
A truck driver in Sömmerda in the German state of Thuringia was hospitalized after police freed him from his vehicle, which had been crushed by a falling tree branch.
The German weather service DWD said the heaviest rains were in southern Germany, estimating that up to 38 litres of rain fell per hour in the Swabia region. Police in Bavaria reported that a home in Straubling was struck by lightning and winds had uprooted trees. Emergency forces in Augsburg had to redirect traffic after a tunnel was filled with rainwater.
The rains covering most of the country aren't expected to ease until Friday afternoon the DWD said, but Germans can expect a reprieve from the wet weather on Saturday, which will be sunny and warm.