Official name: Lao People's Democratic Republic
Area: 236,800 square kilometers (91,400 square miles)
Highest point on mainland: Mount Bia (2,820 meters/9,252 feet)
Lowest point on land: Mekong River (70 meters/230 feet)
Hemispheres: Northern and Eastern
Time zone: 7 P.M. = noon GMT
Longest distances: 1,162 kilometers (722 miles) from south-southeast to north-northwest; 478 kilometers (297 miles) from east-northeast to west-southwest
Land boundaries: 5,083 kilometers (3,151 miles) total boundary length; Myanmar (Burma) 235 kilometers (146 miles); Cambodia 541 kilometers (335 miles); China 423 kilometers (262 miles); Thailand 1,754 kilometers (1087 miles); Vietnam 2,130 kilometers (1321 miles)
Territorial sea limits: None
Laos, the only landlocked Southeast Asian country, lies at the heart of the Indochina h2ninsula. With an area of 236,800 square kilometers (91,400 square miles), it is slightly larger than the state of Utah and contains sixteen provinces.
Laos has no territories or dependencies.
Laos has a tropical monsoon climate with three seasons: a cool, dry season in November through February; a hot, dry season in March and April; and a rainy season in May through October. Temperatures average 28°C (82°F), ranging from highs of 40°C (104°F) along the Mekong in March and April to lows of 5°C (41°F) in the mountains in January. Humidity averages 70 to 80 percent. Annual rainfall in Laos averages 175 centimeters (69 inches). Most of this rain occurs during the southwest monsoon between May and October. Rainfall can be anywhere from 127 to 229 centimeters (50 to 90 inches) during this period.
Laos consists of a northern region centered on the Mekong River valley, with a narrower panhandle extending off to the southeast. Less than three-fifths of the national territory is contained in the northern section of the country, and over two-fifths is in the country's southern panhandle. Away from the Mekong, the high mountains of the Annamese Cordillera extend across the country.
Laos is a landlocked nation. The closest sea is the Gulf of Tonkin of the Pacific Ocean.
Laos boasts few lakes. The largest by far is Ngum Reservoir.
The Mekong River and its tributaries drain almost all of Laos. Only a few small rivers in the east flow into Vietnam and from there to the Pacific Ocean. The Mekong flows through Laos for 1,805 kilometers (1,122 miles) and is the center of its economic life. The north is the only part of the country where the river is entirely within Laos's borders. The Mekong's tributaries in the north include the Tha and the Ou Rivers, as well as the Ngum River. In the south the main tributaries are the Kading, Bangfai, Banghiang, and Dôn Rivers. Another large tributary, the Kong, flows south from Laos into Cambodia before joining the Mekong.
The Khone waterfall, one of the largest waterfalls in southeast Asia, was a barrier to invaders who wanted to enter Laos by river.
There are no desert regions in Laos.
The most extensive and fertile flatlands are found in the valleys and flood plains of the Mekong and its tributaries. Laos has several areas of karst limestone hill formations, including Vangvieng in the northwest and Nam Phoun, a National Biodiversity Area in the northeast.
Northern and northeastern Laos, north of the Laotian panhandle and away from the Mekong River, is characterized by rugged mountain terrain. The main ranges run from northeast to southwest, and are sharp-crested and steep-sloped. Several ranges are around 1,524 meters (5,000 feet) in height, and many peaks are well over 1,829 meters (6,000 feet). The country's highest mountain, Mount Bia (Phou Bia), rising 2,820 meters (9,252 feet) above sea level, is situated here, near the beginning of the panhandle.
The chief topographic feature of the Laotian panhandle is the Annamese Cordillera, which runs along the entire eastern side of this region. The chain parallels the flow of the Mekong River. The mountains in its upper portion have deep valleys and rugged peaks over 1,524 meters (5,000 feet), including Mount Rao (2,234 meters/7,331 feet). South of the Cammon Plateau, the chain enters a region characterized by steep ridges and peaks and sinkholes, followed by the Bolovens Plateau. From this point to the southern end of Laos, the chain again becomes very rugged.
Where the Mekong River enters Laos, it runs through steep limestone gorges north of the city of Louangphrabang. The Hin Boon River in central Laos cuts through narrow limestone canyons.
The Plain of Jars (Thong Hai Hin) is located on the Xiangkhoang Plateau, in the northern part of the country, lying mostly between about 1,015 and 1,219 meters (3,330 and 4,000 feet) above sea level. The Phouane Plateau is another major plateau region in northern Laos. At the neck of the panhandle section, several plateaus, including the Cammon and Nakai plateaus, buttress the Annamese Cordillera. The fertile Bolovens Plateau in the south, rising to about 1,067 meters (3,500 feet), is almost completely encircled by a high escarpment.
Many bomb craters from the United States' aerial bombardment of Laos in the 1960s and 1970s, during the Vietnam War, have filled with water, becoming ponds.
The Nam Ngum hydropower dam created the Ngum reservoir, which covers an area of 250 square kilometers (96 square miles). About one-quarter of the Nakai Plateau is slated to be flooded by the Nam Theun II dam project.
Eliot, Joshua, and Jane Bickersteth. Footprint Laos Handbook. Bath, UK: Footprint Handbooks, 2000.
Savada, Andrea Matles, ed. Laos: A Country Study. Washington DC: Library of Congress, 1996.
Stuart-Fox, Martin. A History of Laos. Cambridge, UK: Cambridge University Press, 1997.