Before explaining in detail the weather variaties during the year, we could say that there is no right or wrong season to visit Vietnam. If you prefer cultural tours of the country, you can travel in Vietnam at any time, with the best balance period in the months of April, May or October or even until the mid of December.
It is a nice idea to discover Vietnam during Tet, Vietnamese traditional New Year which may be in January or early February, but not ideal as the whole country is on the move so you have to plan carefully your trip.
If you prefer the beach, you should avoid the moosoon season in the center of Vietnam from October to December but you could enjoy wonderful wearther in the southern beaches such as Phu Quoc or Mui Ne
Vietnam has a very diverse climate as its territory expanded on many latitudes and spread in various altitudes approximately 1800 km from top to toe. When a region is wet, cold or rainy, we always find another pleasantly sunny.
Located in the monsoon zone of South East Asia, Vietnam has two typical monsoon seasons. Between October and March, the north-east monsoon affects mainly the area north of Danang. It makes cool, wet winters on all areas north of Nha Trang, mild and dry weather in the south. In April-May to October, the south-west monsoon pushes its accumulated moisture-laden winds in the Indian Ocean and the Gulf of Siam. It provides a warm and humid weather throughout the country, except in protected mountain areas (as in low-lying coastal areas of the center or the Red River Delta).
The seasons are different for each part of Vietnam
The north has four seasons:
Winter time from December to February makes pretty cool and humid weather, especially in the mountains (where the temperature often drops below 10 ° C) and gray skyline. February and March are characterized by an eternal drizzle the Vietnamese called ”dust rain”.
Summer starts in April-May, high humidity, rain, often with a heat haze. In June, July and August, summer is in full swing with a temperature of 28-38 ° C, possibility of heavy showers late in the day or night.
September, October and November are considered as the best season to visit North Vietnam: it is 20 to 30 ° C, low humidity, sunny and blue skies.
Between late July and September, devastating typhoons come from the ocean that would cause landslides in mountainous regions and destroy roads and tracks.
The Centre has two seasons:
Unlike the south of the country (region of Saigon and the Mekong Delta) and the Central Highlands, coastal lowlands of the Centre are not affected by the summer monsoon from April-May to September. Therefore, It is usually a good weather with a haze of heat, the temperature can rise up to 40 ° C in July and August.
October-December is the stormy time, with heavy rains that would result in more or less significant flooding on the coastal strip (Hue, Hoian).
Dry season lasts from January to August in Nha Trang, but it is from December to March-April in Dalat and the rest of the Central Highlands.
The South of Vietnam:
This area has a sub-equatorial climate with two different seasons. The wet season lasts from May to October, with a haze of heat and heavy rains (in the form of brief but torrential downpours almost daily, usually after – noon). The dry season lasts from December to April, with sunny weather and low humidity (especially between February and April), temperature is around 27-33 ° C.