Lower Saxony borders on (from north and clockwise) the North Sea, the states of Schleswig-Holstein, Hamburg, Mecklenburg-Vorpommern, Brandenburg, Saxony-Anhalt, Thuringia, Hesse and North Rhine-Westphalia, and the Netherlands (Drenthe, Groningen and Overijssel). Furthermore, the state of Bremen forms two enclaves within Lower Saxony, one being the city of Bremen, the other, its seaport city of Bremerhaven. In fact, Lower Saxony borders more neighbours than any other single Bundesland. The state's principal cities include the state capital Hanover, Braunschweig (Brunswick), Luneburg, Osnabruck, Oldenburg, Hildesheim, Wolfenbuttel, Wolfsburg, and Gottingen.
Lower Saxony has a natural boundary in the north in the North Sea and the lower and middle reaches of the River Elbe, although parts of the city of Hamburg lie south of the Elbe. The state and city of Bremen is an enclave entirely surrounded by Lower Saxony. The Bremen/Oldenburg Metropolitan Region is a cooperative body for the enclave area. To the southeast, the state border runs through the Harz, low mountains that are part of the German Central Uplands. The northeast and west of the state, which form roughly three-quarters of its land area, belong to the North German Plain, while the south is in the Lower Saxon Hills, including the Weser Uplands, Leine Uplands, Schaumburg Land, Brunswick Land, Untereichsfeld, Elm, and Lappwald. In northeast, Lower Saxony is Luneburg Heath. The heath is dominated by the poor, sandy soils of the geest, whilst in the central east and southeast in the loess borde zone, productive soils with high natural fertility occur. Under these conditions“with loam and sand-containing soils“the land is well-developed agriculturally. In the west lie the County of Bentheim, Osnabruck Land, Emsland, Oldenburg Land, Ammerland, Oldenburg Munsterland, and on the coast East Frisia.
Lower Saxony falls climatically into the north temperate zone of central Europe that is affected by prevailing Westerlies and is located in a transition zone between the maritime climate of Western Europe and the continental climate of Eastern Europe. This transition is clearly noticeable within the state: whilst the northwest experiences an Atlantic (North Sea coastal) to Sub-Atlantic climate, with comparatively low variations in temperature during the course of the year and a surplus water budget, the climate towards the southeast is increasingly affected by the Continent. This is clearly shown by greater temperature variations between the summer and winter halves of the year and in lower and more variable amounts of precipitation across the year. This sub-continental effect is most sharply seen in the Wendland, in the Weser Uplands (Hamelin to Gottingen) and in the area of Helmstedt. The highest levels of precipitation are experienced in the Harz because the Lower Saxon part forms the windward side of this mountain range against which orographic rain falls. The average annual temperature is 8 ĄC (7.5 ĄC in the Altes Land and 8.5 ĄC in the district of Cloppenburg).