The extreme weather follows soaring temperatures in both countries, with Germany’s Rhineland-Palatinate region reaching 36.5C.
Severe thunderstorms have caused devastation in Germany and Belgium as both countries experienced heavy rainfall.
In Germany, the intense heat of the preceding days triggered the first of the major storms, with the North Rhine-Westphalia, Lower Saxony, Bavaria and Baden-Württemberg regions most affected.
The storms are expected to move towards Schleswig-Holstein and Mecklenburg-Western Pomerania in the coming days.
Severe weather warnings were in place in North Rhine-Westphalia, where rain and hail flooded streets, motorways and cellars.
The emergency services were deployed to the area but reported there were no serious injuries.
Flooding also struck Baden-Württemberg, where the Saalbach river broke its banks.
In Bavaria, the fire department was dispatched after a train collided with a fallen tree obstructing the tracks.
Heavy rain also fell in East Frisia, where a hospital had to be secured against flooding.
In Belgium, the Royal Meteorological Institute (KMI) issued an amber warning in the Limburg and Liège Provinces while the rest of the country remains under a code yellow.
Brussels and the Antwerp province have had to close off streets due to flooding, and in the Antwerp district of Wilrijk, 39mm of rain fell in just one hour.
The KMI said that August’s rainfall record has already been broken, with 100mm of rainfall recorded at the KMI weather station in Brussels this month, compared to the average of 86.5mm.