In western Germany, people must expect strong thunderstorms early on Wednesday morning.
For parts of North Rhine-Westphalia, Hesse, Rhineland-Palatinate and Lower Saxony, the German Weather Service (DWD) published official warnings at night.
"A low-pressure channel over south-west Germany is shifting north-east with warm, humid and unstable air," it said.
In addition, showery rain and locally heavy rain must be expected.
Storm gusts with speeds of up to 70 kilometers per hour are possible.
The DWD warned that people should pay particular attention to falling branches, roof tiles and other objects.
Temporary traffic delays are possible during the downpour.
According to the DWD, the thunderstorms should initially weaken a little during the day, but get stronger again at noon.
Even then, local heavy rain and storms are possible again.
According to the forecast, hail and squalls are not excluded.