Geography and urban development of Dresden temperatures are almost the same as those in cities in southwest Germany; on average 10.2°C per year. In hot summers, Dresden is between the hot Lusatia and the milder Ore Mountains. Both regions are characterised by strong winters: temperatures of −20°C are not impossible in Dresden. The driest months are February and March, with precipitation of 40 mm. Spring months have often been arid in the last couple of years (with less than 10 mm of precipitation). The most precipitation falls in July and August, at 60 mm per month. Due to its location on the banks of the Elbe
Accession of Hamburg to the German Customs Union (Zollverein) to the wishes of all concerned. The Hamburg Senate, like others, had to give up essential parts of its state independence, but this was necessary to achieve an agreement. The Burgerschaft ratified the constitution on 15 May 15, 1867 and it came into force on 1 July 1, 1867, founding the North German Federation. Although Hamburg joined the North German Federation, it remained outside the Customs Union. The federation's constitution included special arrangements for Hamburg and the other Hanseatic cities: Article 34: The Hanseatic cities of Lübeck, Bremen and Hamburg with appropriate districts for this purpose or their surrounding area,