Vietnam is a country with many different weather systems. In general terms, Vietnam has a tropical monsoon climate, with monsoon rains, warm temperatures (on average 24-34⁰C), and high humidity all year round. The weather can be divided into two main seasons: the rainy season (April to September) and the dry season (October to March). There is no ideal time to visit Vietnam as a whole, yet any time of the year might be great for some destinations.
Weather in Northern Vietnam
Weather in Halong Bay, Hanoi, Sapa, Ha Giang, Ninh Binh
There are two distinct seasons in the north: a cold weather from November to March and a warm to hot wet season from April to October. It might be extremely cold and frosty in December and January, especially in the Far North. The temperature may fall to 2⁰C, which is not comfortable for the elderly and children. There might be also dense mists, which can reduce visibility in such destinations as Sapa and Halong Bay. However, from November to March is still considered better time to visit the North. The average temperature is around 25⁰C. It is dry and suitable for both sightseeing and adventurous trips.
From April to October, it is very hot and humid. Between June and July, the temperature may be over 40⁰C in some cities. The north experiences the highest rainfall in this period, too. It may rain consecutively in a week, and the volume of rainfall may reach 600 mm per month. It is highly recommended that travelers should not have intrepid escapade to the Far North in this season, as the roads are bumpy and slippery. If you want to explore the beauty of Halong Bay, Hanoi, or Ninh Binh, but cannot stand the huge flocks of tourists at peak seasons, coming in summer might be a great choice.
Weather in Central Vietnam
Central Vietnam is a transitionary climate-wise area from the North to the South. Being shielded by the Truong Son mountain range, the rains of the southwest monsoon cannot make it to the coast. Therefore, from April to September, though the coastal areas have some rain, the rainfall is much less than other regions. On the contrary, the weather is extremely hot and dry, and the temperature may reach 45⁰C.
In contrast, from September to December, the middle part, especially Hue, Danang, and Hoi An, receive remarkably high rainfall. Central Vietnam is also affected by typhoons and storms between August and November, resulting in severe flood in some regions.
The further south areas like Nha Trang and Mui Ne are less affected by natural disasters and have much more pleasant weather with lots of sunshine and high humidity. It is the perfect weather to explore the beaches.
Weather in Southern Vietnam
This is the region which has the most pleasant weather. Between April and September, the southern part of Vietnam, especially the Mekong Delta, receives lots of rain and has hot and humid weather during the southwest monsoon. June and July are extremely wet. At this time there is a high likelihood of flood in Saigon. The roads may be covered by water. And the southernmost island of Phu Quoc may have poor weather and rough seas.
In contrast, the weather from November to March is excellent, especially in Phu Quoc. The climate is pleasant with the average temperature of 30⁰C, clear blue skies, calm sea water, lower humidity, and higher visibility.