The Great Southern covers 39,007 square kilometres on the south coast of Western Australia, bordering 250km of the Southern Ocean and extending 200km inland. It comprises about 1.5 per cent of Western Australia's total land area.
The Great Southern enjoys a milder climate than much of the rest of Western Australia. Most of the Great Southern has reliable growing seasons most of the time, although nowhere is immune to Australia’s periodic droughts and the impacts of a changing climate. Annual rainfall decreases along the coast from west to east, and inland away from the coast but the entire Great Southern is within productive climate zones.
Land types range from mallee scrub in the north-east to karri forests in the south-west of the region. Two ancient ranges of hills, the Stirling Range and the Porongurup Range, rise in the central Great Southern flanking the Kalgan River valley. The Stirling Range includes Bluff Knoll, at 1095m the highest peak in the southern half of Western Australia.
Much of the Great Southern’s arable land was cleared for primary production during the 20th century. Implementing sustainability principles assumed increasing importance toward the close of the 20th century and a strong landcare ethic has emerged amongst landholders and managers.
Eleven local government areas are encompassed by the Great Southern.