Bas-Rhin (bɑ.ʁɛ̃; Alsatian: Unterelsàss, ‘s Unterlànd or ‘s Ingerlànd; traditional Niederrhein; Lower Rhine) is a department in Alsace which is a part of the Grand Est super-region of France. The name means 'Lower Rhine', referring to its lower altitude among the two French Rhine departments: it is downstream of the Haut-Rhin (Upper Rhine) department. Note that both belong to the European Upper Rhine region. It is, with the Haut-Rhin (Upper Rhine), one of the two departments of the traditional Alsace region which until 1871, also included the area now known as the Territoire de Belfort. The more populous and densely populated of the pair, it had 1,148,073 inhabitants in 2020. The prefecture is based in Strasbourg. The INSEE and Post Code is 67. On 1 January 2021, the departemental councils of Bas-Rhin and Haut-Rhin merged into the European Collectivity of Alsace. The inhabitants of the department are known as Bas-Rhinois or Bas-Rhinoises. The Rhine has always been of great historical and economic importance to the area, and it forms the eastern border of Bas-Rhin. The area is also home to some of the foothills of the Vosges Mountains. To the north of Bas-Rhin lies the Palatinate forest (Pfälzerwald) in the German State of Rhineland-Palatinate, and the German State of Baden-Württemberg lies to the east. To the south lies the department of Haut-Rhin, the town of Colmar and southern Alsace, and to the west the department of Moselle. On its south-western corner, Bas-Rhin also joins the department of Vosges. The most populous commune is Strasbourg, the prefecture. As of 2020, there are 7 communes with more than 15,000 inhabitants: The Bas-Rhin has a continental-type climate, characterised by cold, dry winters and hot, stormy summers, due to the western protection provided by the Vosges. The average annual temperature is in the lowlands (Entzheim) and on high ground. The annual maximum temperature is high (). The average rainfall is per year. Established according to data from the Infoclimat station at Strasbourg-Entzheim (the airport), over the period from 1961 to 1990.