The country more than 1,600 kms long from North to South. And the country was divided into two parts North & South so the weather also divided too, from a temperate to a tropical climate. While this variety makes travel to Vietnam a year-round destination will be Ok.
Especially if you travel to Vietnam in spring (March to April). So It’s the best time to visit. Because when days are generally pleasant, temperatures are moderate and rainfall is light.