In
Hanoi as well as the North of Viet Nam, there are 4 seasons in a year, include: spring, summer, autumn and winter. They change obviously.
January, February and March are often known as Spring because they are the beginning of a year. In fact, however, in January and February, the weather in Hanoi is really cold. The North-east monsoons (known as the cold air masses which come from Asia continent to the South, the cold air come along with them) continuously blow to the North of Viet Nam (also called Tonkin). There is time that snow appeared in
Sapa and Fansipan in Lao Cai province and Mau Son Mountain in Lang Son province (this is an extremely rare phenomenon in a tropical country as Vietnam).
Therefore in fact, Hanoi weather is still in the
middle of winter in January and February. The weather is really cold, the average temperature is often about 15-18 degree Celsius, or even colder, about 10-12 degree Celsius.