The islands of Wallis and Futuna, 250 km apart, are quite dissimilar.
Wallis (159 square km including adjacent islands) is fairly flat, with verdant volcanic hillsides rising gently to Mt. Lulu Fakahega (145 meters). There are freshwater crater lakes (Lalolalo, Lanutavake, and others). The main island, Uvéa, and 10 other volcanic islands in the eastern half of the lagoon are surrounded by a barrier reef bearing 12 smaller coral islands, many with fine beaches. Five passes breach this reef, but large ships bound for Mata-Utu wharf enter the lagoon through Honikulu Pass, the southernmost.
Futuna and Alofi, together totaling 115 square km, are mountainous, with Mt. Puke on Futuna reaching 524 meters. Futuna is near a fracture where the Pacific Plate pushes under the Indo-Australian Plate and major earthquakes do occur. Though there are many freshwater springs on Futuna, Alofi two km to the southeast is uninhabited due to a lack of water. A reef fringes the sandy north coast of Alofi; the south coast features high cliffs. Futuna has no lagoon.
As in neighboring Samoa, the climate is hot and humid year-round, with an annual average temperature of 27°C. Rainfall is heavy at more than 3,000 mm a year, usually falling in the late afternoon or night. The hurricane season in the islands is November—April, and many storms form in the area between Wallis and Samoa. During the drier season, May—October, the islands are cooled somewhat by the refreshing southeast trade winds.