Lao Cai: Sa Pa forests covered by snow
Another intense cold spell hit the northern mountainous province of Lao Cai on January 31 with the temperature going down to 1.2 degrees Celsius, according to the local weather forecast station.
Located in the monsoon zone, Vietnam enjoys a warm and humid climate from north to south.
A "frontier" climate however seems to be in the vicinity of Da Nang. And "winter" exists only in the north, beyond the famous pass of Cloud, while in the south it is almost always hot.
Vietnam is very long and therefore climant areas are very different between regions (North, Central and South). This is why we can say that there is no good season, and no bad season in Vietnam because if it is good in the north but not in the South and vice versa.
So go to Vietnam anytime as you want! You'll get the climate, never regret.