The climate of the Po valley is classified as humid subtropical (Cfa) under the Köppen climate classification, a type of climate commonly referred to as "continental", that features severe winters and warm summers and heavy rains in spring and autumn. The legislative body of the Italian communes is the City Council ("Consiglio Comunale"), which, in towns having between 100,000 and 250,000 population, is composed by 32 councillors elected every five years with a proportional system, contextually to the mayoral elections. The executive body is the City Committee ("Giunta Comunale"), composed by 12 assessors, that is nominated and presided over by a directly elected mayor. The current mayor of Ferrara is Tiziano Tagliani of the Democratic Party. The urban organisation is governed by the Italian Constitution (art. 114), the Municipal Statute and several laws, notably the Legislative Decree 267/2000 or Unified Text on Local Administration ("Testo Unico degli Enti Locali"). The current division of the seats in the city council, after the 2019 local election, is the following:   The imposing Este Castle, sited in the very centre of the town, is iconic of Ferrara. A very large manor house featuring four massive bastions and a moat, it was erected in 1385 by architect Bartolino da Novara with the function to protect the town from external threats and to serve as a fortified residence for the Este family. It was extensively renovated in the 15th and 16th centuries. The Cathedral of Saint George, designed by Wiligelmus and consecrated in 1135, is one of the finest examples of Romanesque architecture. The duomo has been renovated many times through the centuries, thus its resulting eclectic style is a harmonious combination of the Romanesque central structure and portal, the Gothic upper part of the façade and the Renaissance campanile. The sculptures of the main portal are attributed to . The upper part of the main façade, with arcades of pointed arches, dates from the 13th century. The recumbent marble lions guarding the portals are copies of the originals, now in the cathedral's museum. An elaborated 13th-century relief depicting the Last Judgement is found in the second storey of the porch. The interior was restored in baroque style in 1712. The marble campanile attributed to Leon Battista Alberti was initiated in 1412 but is still incomplete, missing one projected additional storey and a dome, as it can be observed from numerous historical prints and paintings on the subject.