Ranong is located on the Kra Isthmus, a narrow strip of land that connects Thailand with the Malay Peninsula, on the west of the Phuket mountain range. It has a long coast on the Andaman Sea. The province is known for having the highest rainfall in Thailand, the rainy season there lasting for about eight months. Its annual rainfall in 1955 totaled 6,699.5 mm, compared to about 1,200 in central Thailand.