Geography of Cambodia
Cambodia is a country in Southeastern Asia, bordering the Gulf of Thailand, between Thailand, Vietnam, and Laos. Its approximate geographical coordinates are 13°N 105°E. Its 2,572 km border is split among Vietnam (1,228 km), Thailand (803 km) and Laos (541 km), as well as 443 km of coastline. Cambodia covers 181,040 square kilometres in the southwestern part of the Indochina peninsula. It lies completely within the tropics; its southernmost points are only slightly more than 10° above the equator. Roughly square in shape, the country is bounded on the north by Thailand and by Laos, on the east and southeast by Vietnam, and on the west by the Gulf of Thailand and by Thailand. Much of the country's area consists of rolling plains. Dominant features are the large, almost centrally located, Tonle Sap (Great Lake) and the Mekong River, which traverses the country from north to south.
Cambodia's climate, like that of the rest of Southeast Asia is dominated by monsoons, which are known as tropical wet and dry because of the distinctly marked seasonal differences. The monsoonal airflows are caused by annual alternating high pressure and low pressure over the Central Asian landmass. In summer, it is very cold. The flow is reversed during the winter, and the northeast monsoon sends back dry air. The southwest monsoon brings the rainy season from mid-May to mid-September or to early October, and the northeast monsoon flow of drier and cooler air lasts from early November to March. The southern third of the country has a two-month dry season; the northern two-thirds, a four-month one. Short transitional periods, which are marked by some difference in humidity but by little change in temperature, intervene between the alternating seasons. Temperatures are fairly uniform throughout the Tonle Sap Basin area, with only small variations from the average annual mean of around 25 °C (77.0 °F). The maximum mean is about 28.0 °C (82.4 °F); the minimum mean, about 22.98 °C (73.36 °F). Maximum temperatures of higher than 32 °C (89.6 °F), however, are common and, just before the start of the rainy season, they may rise to more than 38 °C (100.4 °F). Minimum temperatures rarely fall below 10 °C (50 °F). January is the coolest month, and April is the warmest. Tropical cyclones that often devastate coastal Vietnam rarely cause damage in Cambodia.
Cambodia's boundaries were for the most part based upon those recognized by France and by neighboring countries during the colonial period. The 800-kilometre boundary with Thailand, coincides with a natural feature, the watershed of the Dangrek Mountains, only in its northern sector. The 541-kilometer border with Laos and the 1,228-kilometer border with Vietnam result largely from French administrative decisions and do not follow major natural features. Border disputes have broken out in the past between Cambodia and Thailand as well as between Cambodia and Vietnam.