Ho Chi Minh City, formerly named Saigon, is the largest city in Vietnam. It was once known as Prey Nokor, an important Khmer sea port prior to annexation by the Vietnamese in the 17th century. Under the name Saigon, it was the capital of the French colony of Cochin-china and later of the independent state of South Vietnam from 1955 to 1975. In 1976, Saigon merged with the surrounding Gia Định Province and was officially renamed Hồ Chí Minh City after Hồ Chí Minh (although the name Sài Gòn is still commonly used.)

The city center is situated on the banks of the Saigon River, 60 kilometers (37 mi) from the South China Sea and 1,760 kilometers (1,090 mi) south of Hanoi, the capital of Vietnam.

The metropolitan area, which consists of the Hồ Chí Minh City metropolitan area, Thủ Dầu Một, Dĩ An, Biên Hòa and surrounding towns, is populated by more than 9 million people, making it the most populous metropolitan area in Vietnam and the countries of the former French Indochina. The Greater Ho Chi Minh City Metropolitan Area, a metropolitan area covering most parts of Đông Nam Bộ plus Tiền Giang and Long An provinces under planning will have an area of 30,000 square kilometers with a population of 20 million inhabitants by 2020. According to the Mercer Human Resource Consulting, Economist Intelligence Unit and ECA International, Ho Chi Minh City is ranked 132 on the list of world's most expensive cities.

Ho Chi Minh City has gone by several different names during its history, reflecting settlement by different ethnic, cultural and political groups. Originally known as Prey Nokor while part of the Khmer Empire, it came to be dubbed Sài Gòn informally by Vietnamese settlers from the north. In the 1690s, Nguyễn Hữu Cảnh, a Vietnamese noble, was sent by the Nguyen rulers of Huế to establish Vietnamese administrative structures in the Mekong Delta and its surroundings. Control of the city and the area passed to the Vietnamese, who gave the city the official name of Gia Định. This name remained until the time of French conquest in the 1860s, when the occupying force adopted the name Saigon for the city, a westernized form of the traditional name.

Immediately after the communist takeover of South Vietnam in 1975, a provisional government renamed the city after Hồ Chí Minh, the pre-eminent but by-then deceased North Vietnamese leader. Even today, however, the informal name of Sài Gòn remains in daily speech both domestically and internationally, especially among the Vietnamese diaspora. In particular, Sài Gòn is still commonly used to refer to District 1.

The city has a tropical climate, specifically a tropical wet and dry climate, with an average humidity of 75%. The year is divided into two distinct seasons. The rainy season, with an average rainfall of about 1,800 millimetres (71 in) annually (about 150 rainy days per year), usually begins in May and ends in late November. The dry season lasts from December to April. The average temperature is 28 °C (82 °F), the highest temperature sometimes reaches 39 °C (102 °F) around noon in late April, while the lowest may fall below 16 °C (61 °F) in the early mornings of late December.

Information based on http://en.wikipedia.org/wiki/Saigon