Burma, which has a total area of 678,500 square kilometres (262,000 sq mi), is the largest country in mainland Southeast Asia, and the 40th-largest in the world. It lies between latitudes 9° and 29°N, and longitudes 92° and 102°E.
It is bordered to the northwest by Chittagong Division of Bangladesh and Mizoram, Manipur, Nagaland and Arunachal Pradesh of India to the northwest. Its north and northeast border straddles the Tibet and Yunnan regions of China for a Sino-Burman border total of 2,185 kilometres (1,358 mi). It is bounded by Laos and Thailand to the southeast. Burma has 1,930 kilometres (1,200 mi) of contiguous coastline along the Bay of Bengal and Andaman Sea to the southwest and the south, which forms one quarter of its total perimeter.
In the north, the Hengduan Shan mountains form the border with China. Hkakabo Razi, located in Kachin State, at an elevation of 5,881 metres (19,295 ft), is the highest point in Burma. Three mountain ranges, namely the Rakhine Yoma, the Bago Yoma, and the Shan Plateau exist within Burma, all of which run north-to-south from the Himalayas. The mountain chains divide Burma's three river systems, which are the Ayeyarwaddy, Salween (Thanlwin), and the Sittaung rivers. The Ayeyarwaddy River, Burma's longest river, nearly 2,170 kilometres (1,348 mi) long, flows into the Gulf of Martaban. Fertile plains exist in the valleys between the mountain chains. The majority of Burma's population lives in the Ayeyarwaddy valley, which is situated between the Rakhine Yoma and the Shan Plateau.
Much of the country lies between the Tropic of Cancer and the Equator. It lies in the monsoon region of Asia, with its coastal regions receiving over 5,000 mm (196.9 in) of rain annually. Annual rainfall in the delta region is approximately 2,500 mm (98.4 in), while average annual rainfall in the Dry Zone, which is located in central Burma, is less than 1,000 mm (39.4 in). Northern regions of the country are the coolest, with average temperatures of 21 °C (70 °F). Coastal and delta regions have an average maximum temperature of 32 °C (89.6 °F).