Vietnam is located in both a tropical and a temperate zone. It is characterized by strong monsoon influences, but has a considerable amount of sun, a high rate of rainfall, and high humidity. Regions located near the tropics and in the mountainous regions are endowed with a temperate climate.

The monsoon climate also influences to the changes of the tropical humidity. In general, in Vietnam there are two seasons, the cold season occurs from November to April and the hot season from May to October. The difference in temperature between the two seasons in southern is almost unnoticeable, averaging 3ºC. The most noticeable variations are found in the northern where differences of 12ºC have been observed. There are essentially four distinct seasons, which are most evident in the northern provinces(from Hai Van Pass toward to the north): Spring, Summer, Autumn, and Winter.

Every year there are 100 rainy days and the average rainfall is 1,500 to 2,000mm. The humidity ranges around 80%. The sunny hours are 1,500 to 2,000 and the average solar radiation of 100kcal/cm2 in a year.

Because Vietnam is affected by the monsoon, that why the average temperature is lower than the other countries which are located in the same longitude in Asia. The annual average temperatures range from 22oC to 27oC. In comparing with these countries, the temperature in winter is colder and in summer is less hotter in Vietnam.