The geology and landscape of the Scenic Rim is largely volcanic in origin, deriving from the prehistoric Tweed Volcano, including the Mount Warning shield volcano, and the Focal Peak and Main Range volcanic rocks. Some areas of sedimentary origin include parts of Mount Barney and eastern Lamington national parks. The deeply weathered, mainly basaltic, soils support rainforest and vine thicket ecosystems, as well as rare eucalypt and grassland communities. The area has a subtropical climate with (at the lowest altitudes) average minimum winter temperatures of 6°C, average maximum summer temperatures of 29°C, and average annual rainfall of 1555 mm.