Iriomote has a tropical rainforest climate. The average annual rainfall of Iriomote is around 2,500mm. Iriomote has a typhoon season that, on average, runs from June to September.
90% of the island is covered by dense jungle and mangrove swamps. 80% of the island is protected state land, and 34.3% of the island forms the Iriomote National Park. The highest point on the island is Mt. Komi (古見岳 Komidake) at 470 meters. Around 21 km northwest (24.558°N 124.00°E) of Iriomote is an active undersea volcano which last erupted in 1924; the summit is 200 m below sea level.
The island is famed for the Iriomote Cat (Prionailurus bengalensis iriomotensis), a Critically Endangered wild cat found only on Iriomote. The population size is estimated to be fewer than 250 adult individuals. In Japanese the cat is called 西表山猫 Iriomote-yamaneko.
The island, together with the rest of Okinawa Prefecture, remained a US-controlled territory until 1972. Iriomote was returned to Japan on 17 June 1972.