Area: 3.324,92 sq. km
Population: 6,232,900 habitants (8/2008).

Administrative divisions:

- 9 urban districts: Hoan Kiem, Ba Dinh, Dong Da, Hai Ba Trung, Tay Ho, Thanh Xuan, Cau Giay, Long Bien, Hoang Mai.
- 2 cities: Ha Dong, Son Tay
- 18 rural districts: Dong Anh, Soc Son, Thanh Tri, Tu Liem, Gia Lam (old Hanoi); Ba Vi, Chuong My, Dan Phuong, Hoai Duc, My Duc, Phu Xuyen, Phuc Tho, Quoc Oai, Thach That, Thanh Oai. Thuong Tin, Ung Hoa (former Ha Tay province) and Me Linh (a former district of Vinh Phuc province).
Ethnic groups: Viet (Kinh), Hoa, Muong, Tay, Dao...
Hanoi is the capital of the Socialist Republic of Vietnam, the center of culture, politics, economy and trade of the whole country.

Hanoi is located in the Red River Delta, in the center of North Vietnam. It is encompassed by Thai Nguyen Province to the north, Vinh Phuc and Ha Tay to the west and south, Bac Giang, Bac Ninh and Hung Yen provinces to the east and south-east.Hanoi means "the hinterland between the rivers" (Ha: river, Noi: interior). Hanoi's territory is washed by the Red River (the portion of the Red River embracing Hanoi is approximately 40km long) and its tributaries, but there are some other rivers flowing through the capital, including Duong, Cau, Ca Lo, Day, Nhue, Tich, To Lich and Kim Nguu.
Climate: Hanoi is situated in a tropical monsoon zone with two main seasons. During the dry season, which lasts from October to April, it is cold and there is very little rainfall, except from January to March, when the weather is still cold but there is some light rain. The wet season, from May to September, is hot with heavy rains and storms. The average annual temperature is 23.2ºC (73.7ºF) and the average annual rainfall is 1,800mm. The average temperature in winter is 17.2ºC (62.9ºF), but can go down to 8ºC (46.4ºF). The average temperature in summer is 29.2ºC (84.6ºF), but can reach up to 39ºC (102.2ºF).