St. Mary Magdalene's flood occurred on and around the feast day of St. Mary Magdalene, 25 July; the passage of a Genoa low 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.