Historical Archive of the City of Cologne included copies of the protocols of the diets of the Hanseatic League. With the 1594 transfer, the Cologne archive became the most important repository of historical material concerning the Hanseatic League and thus concerning the history of Northern Germany in general, only matched by the municipal archives of Lübeck. On 27 February 1602, the city council ordered that books on jurisdiction and administration were to be systematically bought at the regularly held Frankfurt Book Fair. These were subsequently stored in the municipal archive and became the basis of the Cologne municipal library. The "Ratsbibliothek" was one of the few Cologne
Cologne In January, the mean temperature is , while the mean temperature in July is . Temperatures can vary significantly over the course of a month with warmer and colder weather. Precipitation is spread evenly throughout the year with a light peak in summer due to showers and thunderstorms. Cologne is regularly affected by flooding from the Rhine and is considered the most flood-prone European city. A city agency ("Stadtentwässerungsbetriebe Köln", "Cologne Urban Drainage Operations") manages an extensive flood control system which includes both permanent and mobile flood walls, protection from rising waters for buildings close to the river banks, monitoring