Savannakhet or officially named Kaysone Phomvihane (Lao: ໄກສອນ ພົມວິຫານ; Thai: ไกสอน พมวิหาน) (population 120,000) is a city in western Laos and the capital of the Savannakhet Province, previously known as Khanthabouli (ຄັນທະບູລີ). This is the second-largest city in Laos, after Vientiane. The city is birthplace of Kaysone Phomvihane, former president of Laos, and was named after him in 2005. Although the old French colonial quarter of the town, along the Mekong River-front, is depressed and crumbling, the town's proximity to Thailand's booming economy has brought about new commercial development in the northern part of the town, near both the river crossing and the bus terminal.
Like all Lao cities, Savannakhet has a mixed population of Lao, Thai, Vietnamese and Chinese, as well as minority peoples from the Lao interior. It has a large 15th-century Buddhist temple, Wat Sainyaphum, a Chinese temple, a Catholic church and a mosque. The Second Thai–Lao Friendship Bridge over the Mekong connects to Mukdahan Province in Thailand. The two-lane, 12-meter-wide (39 ft), 1,600-meter-long (5,250 ft) bridge opened to the general public on January 9, 2007.
The city is served by Savannakhet Airport.
Savannakhet features a tropical savanna climate (Aw) according to Köppen climate classification with a little subtropical climate characteristics as the city located 16.5° north of the equator. The hottest month is April (mean = 29.5 °C (85.1 °F)) with temperature ranging from 23.9 °C (75.0 °F) to 35.2 °C (95.4 °F), while the coolest month is December (mean = 21.7 °C (71.1 °F)) with temperature ranging from 15.2 °C (59.4 °F) to 28.7 °C (83.7 °F). The diurnal temperature variation seems to be greater during winter due to dry conditions. The city experiences dry season during winter months and wet season during summer months due to activation of monsoon. The driest month is December with precipitation total 2.0 millimetres (0.079 in), while the wettest month is August with precipitation total 323.1 millimetres (12.72 in).