In Armagnac, there are several local soils. Bas-Armagnac, Armagnac-Ténarèze and Haut-Armagnac make up a vine leaf-shaped wine area which contains 15,000 hectares of vines planted across three counties: Gers, Landes and Lot-et-Garonne. The climate is temperate and mild. The ocean's damp influence, attenuated by the Landes forests, is especially prevalent in the West of the Armagnac region. In the East, the Mediterranean climate is characterised by the Autan wind.
Bas-Armagnac to the west is an undulating area; the vines grow in clay-sand soils which are high in acidity, in some places mixed with iron, hence the name 'sables fauves' or tawny sands. Boulbène topsoil, the characteristic regional sediment, is rich in limestone. This zone produces light, fruity, delicate and very well reputed eaux-de-vie.
Armagnac-Ténarèze in the centre is a transition zone with rich boulbène topsoil and clay-limestone soil. The eaux-de-vie from this zone are generally full-flavoured, reaching their peak after long ageing.
Haut-Armagnac to the South and East is large and sprawling. The hills have chalky and clay-limestone soils whose valleys are sometimes covered by a rich topsoil known as boulbène. The vines are found here in a few pockets.