Geography
The village lies on the Hoang Lien Son Alps, known in English as the Tonkinese Alps. To the South West of Sa Pa, on this beautiful alp, is the 3143m high Fanxipan Mountain, known as the roof of Indochina – the tallest mountain not only in Vietnam but in all of Indochina. Between Fanxipan Mountain and Sa Pa town is Muong Hoa valley, which is terraced into wet staircase rice paddies.

Demographics
The village of Sa Pa is rich in culture and ethnicity. Out of its 36,000 scattered population, the Kinh group (who are the ethnic majority in Vietnam) only make up 15%. Most inhabitants of Sa Pa are ethnic minorities: Hmong 52%, Dao 25%, Tay 5%, Giay 2% and a small number of Xa Pho, who up to this day still preserve very much of their traditional life style, culture and clothing.

History
The area was originally inhabited by the ethnic groups H’Mong, Dao, Tay and Giay. The spectacular site was first discovered by the French around the 1880s. In 1891, along with the whole of Lao Cai province, Sa Pa was officially incorporated into colonial Vietnam and acted as a major defense point in the North West.
Fascinated by the town’s lust nature, clear air and cool climate (which strongly contrasts with the humidity and heat of the rest of the country), the French colonizers quickly turned Sapa into a retreat center. A flux of missionaries, militaries and wealthy business men came here building sanitariums, villas and churches; turning parts of the town into pleasant European villages.

Nowadays, Sapa is once again open for tourists, waiting to share its secrets and surprises with everyone. There are many hotels in Sapa for staying.
Sapa weather and climate information - the best time to travel to Sapa. The climate of Sapa is highly seasonal, with a subtropical climate in the summer and a temperate climate during the winter. Average temperature for Sapa town is 15.4ºC, with a maximum of 29.4ºC and a minimum of 1ºC. Sapa also experiences a marked wet season from May to September, with the heaviest rainfall occurring in July and August. The weather is also notorious for changing frequently and quickly. It is said that only in Sapa, one can experience many different seasons within only one day.

The best time to travel
For the most pleasant weather, the best times to visit Sapa is March and May or mid-September to early December. While trips can be enjoyed year-round, the winters in Sapa get cold, with some fog and drizzle, and the summers have the hottest weather and higher chances of rain, with the rainy season starting in May through September. If possible, it is recommended to go to Sapa during the week, since the weekend markets can be more crowded with international tourists.
Source: getvietnamvisa.com