The climate in Vietnam is monsoon. And this means that the weather in Vietnam is two main seasons that are dictated by the influences of the south-western monsoon from April to September and the northeast monsoon from October to the end of March or in early April.
It is worth remembering that the South-West Musson brings more warm and wet weather, and the northeast monsoon is a cooler and less humid.
You can mentally split the country into three parts - north, center and south. In these parts of Vietnam, the weather can even differ at the same time. But overall the temperature is constant throughout the year, with the exception of Hanoi and the northernmost part of the country (where it can be very cold in December and January), as well as central Highlands (where it can be a little cooler than in the rest of the country all year round) .
In North Vietnam, as I wrote above, it is rather cool and even cold (because of the northeast monsoon) from November to March and warmth and hot from April to October). December and January in particular can be quite cold and this is not the best time for the visit. This time of year can also be heavy fogs, which are forced for several days - all this leads to extremely poor visibility in places such as Sap and Halong Bay.
The most wet months of the year in Hanoi -Iyul and August, the most dry - December and January.
Central Vietnam is a kind of transition area from north to south, and accordingly, the weather is the best there. Since the coastline of this part is protected by the Mountains of Chyon Sleep, rains that come with the southwestern monsoon, they simply do not spill on the coast, so that in the period from April to September there is a little rain, but is clearly less than in other parts of the country.
But these pleasant days also pass when the northeast monsoons are beginning to blow, from September to December, and rains are shedding the northern plot of Central Vietnam (from Hoian and Dananga to Hue and Dongha). These regions may also be affected during the typhoon season in the western part of the Pacific Ocean - strong storms are collapsed on the shores from August to November, in particular, hesitantly fills Hoian (in October or November). Nothing pleasant!
More southern coastal zones of Central Vietnam (from Nha Trang to Muin) are less susceptible to rain - here is generally land and more sunny.
Since the Mountain Range of Chyon Slets does not protect South Vietnam, especially in the Mekong River Delta, there is a lot of rains and hot wet weather during the southwestern monsoon from April to September, and June and July, especially wet months.
At this time, you will most likely become a witness of small flooding in Saigon (Ho Chi Minh City), and on the island of Fukuoka during these months, very unfavorable weather conditions and the restless sea.
The average annual temperature, in general, above, on the plains than in the mountains, and above in the south than in the north. Temperature fluctuations are lower in the southern plains around Ho Chi Minh City and in the Mekong River Delta - there is always somewhere between 21 and 28 ° C throughout the year. Seasonal fluctuations in the mountains and in the north are much more pronounced, with temperatures in the range from 5 ° C in December and January and to 37 ° C in July and August.
So, when's the best time for a visit to Vietnam? This question cannot be answered unequivocally. In general, the northern directions, such as Hanoi and Sap, are magnificent in October, November and December - at this time there may be a small rain, but in general, clear sky and good weather conditions.
The coastal zone from Hue to Nyachang is good to visit in the first half of the year, from January to July, while in Saigon and to the resorts in the Mekong Delta is better to go from November to February or March. In general, the warmer month in the country - April, and the coldest month is December. September is the most rainy month, and February is the most dry. Water here is pretty warm always, so that this is not worth worrying.