St. Mary Magdalene's flood (German: Magdalenenhochwasser) was the largest recorded flood in central Europe[1] with water levels exceeding those of the 2002 European floods. It occurred in July 1342 on and around the feast day of St. Mary Magdalene which corresponds to 22 July in today's calendar.
The rivers Rhine, Moselle, Main, Danube, Weser, Werra, Unstrut, Elbe, Vltava and their tributaries inundated large areas. Even the river Eider north of Hamburg flooded the surrounding land. Many towns such as Cologne, Mainz, Frankfurt am Main, Würzburg, Regensburg, Passau and Vienna were seriously damaged. The affected area extended to Carinthia and northern Italy.
It appears that after a prolonged hot and dry period continuous rainfalls occurred which lasted several consecutive days and amounted to more than half of the mean yearly precipitation. Since the dry soil was unable to absorb such amounts of water, the surface runoff washed away large areas of fertile soil and caused huge inundations destroying houses, mills and bridges. In Würzburg, the then famous Steinerne Brücke (Stone Bridge) was taken away and in Cologne it is said that a rowing boat could pass over the city's fortifications. The overall number of casualties is not known, but it is believed that alone in the Danube area 6000 people were killed.
It is assumed that the loss of fertile soil led to a serious drop in agricultural production. In addition, the following summers were wet and cold, so that the population suffered from widespread famine. Whether the spreading of the Black Death between 1348 and 1350 killing at least a third of the population in central Europe was facilitated by the weakened condition of the population is a matter of discussion.