Alderney is similar to the other Channel Islands in having sheer cliffs broken by stretches of sandy beach and dunes. The highest point is on the central plateau of the island at 296ft.[13]
Its climate is temperate, moderated by the sea, and summers are usually warmer than elsewhere in the British Isles.
Alderney and its surrounding islets support a rich flora and fauna. Trees are rather scarce, as many were cut down in the 17th century to fuel the lighthouses on Alderney and the Casquets. Those trees that remain include some cabbage trees (due to the mild climate - often miscalled "palms" but of the lily family.), and there are now some small woods dotted about the island. Puffins on Burhou and gannets on Les Étacs just off Alderney are a favourite of many visitors to the island. The Blonde hedgehog is a species native to Alderney. The island had its own breed of cattle, called the Alderney. The pure breed became extinct in 1944, but hybrids remain elsewhere, though no longer in Alderney itself. In August 2005, the west coast of Alderney and associated islands, including Burhou and Ortac, were designated as Ramsar wetlands of international importance.
The island is surrounded by rocks, which have caused hundreds of wrecks. There are two treacherous tidal streams on either side of the island: the Swinge between Alderney and Burhou, just outside the harbour, and Le Raz between the island and the Norman mainland. The Corbet Rock lies in the Swinge.
