Sa Pa District is in Lào Cai Province, northwest Vietnam, 380 km northwest of Hanoi close to the border with China. The Hoàng Liên Son range of mountains dominates the district, which is at the eastern extremity of the Himalayas. This range includes Vietnam's highest mountain, Fan Si Pan, at a height of 3143 m above sea level. In addition, other mountains like Aurora & J (where the sun appears at sunrise) complete a very steep terrain. The town of Sa Pa lies at an elevation of about 1500 meters (4,921 feet) elevation. The climate is moderate and rainy in summer (May—August), and foggy and cold with occasional snowfalls in winter.
Sa Pa is a quiet mountain town and home to a great diversity of ethnic minority peoples. The total population of 36,000 consists mostly of minority groups. Besides the Kinh (Viet) people (15 percent) there are mainly five ethnic groups in Sa Pa: Hmong 52 percent, Dao 25 percent, Tay five percent, Giay two percent, and a small number of Xa Pho. Approximately 7,000 live in Sa Pa, the other 36,000 being scattered in small communes throughout the district.
Most of the ethnic minority people work their land on sloping terraces since the vast majority of the land is mountainous. Their staple foods are rice and corn. Rice, by its very nature of being a labour-intensive crop, makes the daily fight for survival paramount. The unique climate in Sa Pa has a major influence on the ethnic minorities who live in the area. With sub-tropical summers, temperate winters and 160 days of mist annually, the influence on agricultural yields and health-related issues is significant.
According to VietKings (Kyluc.vn)