Tempest Island, also known as the Island of Storms, is one of several treacherous islands in the Strid estuary located off the coast of Malabal Tor in northwestern Valenwood. It is infamous for the unnatural storms that originate there. Surrounded by sand bars and shifting channels and covered in dense jungle, the island has never been fully explored by any civilized authority. A network of natural caves run beneath the island, offering shelter from the unpredictable weather above.
The island was once colonized by the Ayleids, whose white limestone ruins cover the landscape. It has long served as a haven for pirates, raiders and fugitives. The island is thought to have been the source of multiple phenomena, such as the Flood of the Era and the Lamia Invasion of 2E 435, both of which were preceded by fierce storms on the island. These events attracted the attention of academics such as Angalmo, but the island's extreme weather limited research.
In 2E 582, a Maormer invasion force began to assemble on Tempest Island to perform a mysterious ritual, harnessing powerful lightning magic in preparation for a planned takeover of Tamriel. The Aldmeri Dominion had originally refused to man a garrison on the island in order to focus on the ongoing Alliance War, but were eventually alerted of the threat. A group of Altmer soldiers led by Battlereeve Alduril were dispatched to the island to drive off the invaders, but progress was immediately blocked by a horde of lamias on the beach. The Undaunted arrived on the island soon afterwards and aided Alduril by fighting through the Maormer camps, destroying their Conduit Stones and killing their leader, Stormreeve Neidir. This dispelled the storm the Maormer had summoned.