Lower Saxony belongs to the heartland of Low German and almost the entire area of today's federal state has Low German as its ancestral language.
What is being spoken?
The dialects in the north belong to Northern Low German (Coastal Low German). In the Lüneburger Heide they transition to Eastphalian that prevails in the south. Frisians originally lived in northwest Lower Saxony, but they slowly adopted Low German as their language from the 15th to 17th centuries. Only in Saterland and on Wangerooge the Frisian language could hold up. In Saterland until today, on Wangerooge until the 20th century.
In south-western Lower Saxony the dialect increasingly blends into Westphalian. The dialect of Osnabrück, for example, can already be clearly assigned to Westphalian.
Where is Low German not spoken?
There are some non-Low German regions in Lower Saxony. There is the Frisian-speaking Saterland (where Low German is widespread as a second language alongside Sater Frisian) and the southernmost tip of Lower Saxony with the villages of Speele, Spiekershausen, Landwehrhagen, Sichelnstein, Benterode, Nienhagen, Uschlag, Dahlheim and Escherode that are speaking a Hessian-influenced dialect.
Miners from the Erzgebirge settled in the Upper Harz in the 16th century and brought their dialect with them. They form a small High German language island. The towns of Hohegeiß, Wieda, Zorge, Bad Sachsa, Walkenried, Steina, Neuhof, Tettenborn and Wiedigshof also located in the Harz Mountains, on the other hand, have a Thuringian dialect.
In Wendland on the eastern edge of Lower Saxony, Polabic, a Slavic language, was widespread until the 18th century.
The vocabulary of the state is recorded in the Lower Saxon Dictionary.