In 1924, Geestemünde and the neighbouring municipality of Lehe were united to become the new city of Wesermünde, and in 1939 Bremerhaven (apart from the overseas port) was removed from the jurisdiction of Bremen and made a part of Wesermünde, then a part of the Prussian Province of Hanover.Bremerhaven was one of the important harbours of emigration in Europe.Most of the US military units and their personnel were assigned to the city's Carl Schurz Kaserne.
To further complicate matters, a treaty between the two cities (as mentioned in Section 8 of Bremerhaven's municipal constitution) makes Bremerhaven responsible for the municipal administration of those parts owned directly by Bremen (known as stadtbremisch).The container terminal is situated on the bank of the river Weser opening to the north-sea.The city has been connected to the autobahn network since the late 1970s.The A 27 runs north-south, east of the city, connecting Bremerhaven to Bremen and Cuxhaven. The Bundesstraße 71 and secondary roads therefore carry most of the heavy lorry traffic.Today, Bremerhaven is therefore part of the city-state of Bremen, being to all intents and purposes a state comprising two cities, while also a city in its own right.
This is complicated somewhat by the fact that the city of Bremen has owned the "overseas port" within Bremerhaven since 1927.
Another million tons of "High-and-Heavy" goods are handled with ro-ro ships.
In 2011 a new panamax-sized lock has replaced the 1897 Kaiserschleuse, then the largest lock worldwide.
Bremerhaven has a temperate maritime climate; severe frost and heat waves with temperatures above 30 °C (86 °F) are rare.
On average, the city receives about 742 mm (29.2 in) of precipitation distributed throughout the year, with a slight peak in the summer months between June and August.
In the wet dock parts, accessible by two large locks, more than 2 million cars are imported or exported every year with 2,3 million in 2014.