The Weser ([ˈveːzɐ]) is a river of Lower Saxony in north-west Germany. It begins at Hannoversch Münden through the confluence of the Werra and Fulda. It passes through the Hanseatic city of Bremen. Its mouth is 50 km (31 mi) further north against the ports of Bremerhaven and Nordenham. The latter is on the Butjadingen Peninsula. It then merges into the North Sea via two highly saline, estuarine mouths.

Werser (Low German)
The Weser near Bad Oeynhausen
Watershed of the Weser
European context: mouth within Germany.
Etymology*weis, Germanic, meaning to flow
Physical characteristics
  locationConfluence of the Fulda and Werra Rivers in Hann. Münden
  coordinates51°25′17″N 9°38′53″E
  elevation116 m (381 ft)
MouthWadden Sea of the North Sea
Between Bremerhaven and Nordenham
53°32′8″N 8°33′56″E
0 m (0 ft)
Length452 km (281 mi)
Basin size46,306 km2 (17,879 sq mi)
  average327 m3/s (11,500 cu ft/s)
Basin features
River systemWeser basin
  leftDiemel, Emmer, Werre, Große Aue, Hunte
  rightAller, Lesum

It connects to the canal network running east-west across the North German Plain.

The river combined with the Werra a dialectal form of Weser runs 744 km (462 mi). This makes up the longest river wholly in Germany. The Weser itself is 452 km (281 mi) long. The Werra rises in Thuringia, the German State south of the main projection (tongue) of Lower Saxony.