The best time to visit Son La are February, May and December.
Driving from Hanoi along National Highway 6 for about 320km, you reach the provincial town of the same name, Son La, on a plateau some 600m above sea level.
Son La province is a mountainous province. It has two grand plateaus also named Son La and Moc Chau, and an immese area of crop fields. There are a lot of valleys, high hills and mountains in Son La.
The climate is divided into two distinct seasons. Winter lasts between October and March of the next year, and summer from April to September.
The annual average temperature is about 21.4oC, the highest temperature is 27oC and the lowest one is 16oC. The annual average rainfall is 1200 – 1600mm, and the average humidity is 81%.