Natural features of Southeast Vietnam are the transitional characteristics of Vietnam geography from the south pole of Central Vietnam to Mekong River Delta. The average height of this region is from a few tens of meters to 200 meters above the sea level. This region includes low plateau surface and undulating hills. The terrain in this area is not deeply divided. Thus, climate in Southeast Vietnam carries many characteristics of sub-equatorial climate. During a year, there is no significant change in climatic conditions. Natural disasters such as hurricanes or floods seldom occur in this area. The network of river is thick and short, including river system of Dong Nai River, Thi Vai River, and Saigon River. There are new alluvial lowlands in hydro-dimensional delta of Dong Nai River in which the former kingdom of mangrove forest used to exist.
There are four main types of weather in Southeast Vietnam. First, it is mild dry weather. This type of weather lasts for several days between December and January. During this time, it is characterized by azure sky, cool air and beautiful sunshine. Second, in hot dry weather, the region is influenced by high pressure from Pacific which forms hot and dry weather. This weather is often seen from late March to early April. In daytime, it is sunny with high temperature. Just when night falls, the heat can be released. Third, it is wet hot weather. This type of weather happens between April and May, going with hot and dry west wind in North Central part of Vietnam. It is generally a period of hot weather pattern appeared in Southeastern provinces. When showers and thunderstorms appear, the weather becomes cooler and moister. In April, the weather in this region is extremely hot. It might be the hottest period in a year. The last type of weather in Southeast Vietnam is hot and less rainy weather. When the southwest monsoon tends to weaken, Pacific high pressure in the South China retreats to the southeast. In case of high pressure dominates the South China Sea and enters Vietnam territory and southern areas, it will occur hot without rainy weather. This situation can last for a few days. Vietnam weather in Southeast during these days is less cloudy, and sunny with light wind; rainstorms can calm the heat. With these types of weather, such places as beaches in Vung Tau or ecological parks in Ho Chi Minh City are ideal choices to escapes the heat.
Overall, weather in Southern Vietnam in general and in Southeastern part in particular is hot and rainy with high humidity. It is a stable tropical monsoon climate dividing into two distinct seasons: dry season and rainy season. The rainy season generally runs from May to the end of October. In the early months of the rainy season, large showers often appear, and then stop soon. In July, August, and September, it is rain heavily. There are nasty rainstorms lasting for 1-2 consecutive days and nights. Yet, in some provinces in the region, seldom do storms happen. The average temperature in the region ranges from 26°C -27°C. The temperature reaches the highest point at about 390C, the lowest point at about 16°C at night and 18°C in the early morning. In dry season, the average humidity is about 76% - 80%, mounting the highest point of 86% in September and the lowest one of 66% in February. The amount of annual rainfall fluctuates from 1800 to 2000mm.
This region is regarded one of the ideal destinations in Vietnam that tourists can visit at any time during a year. Vietnam weather in the south has temperature ranging between 25 - 35°C year round. As the position of the region is near equator, thus, local people do not have a chance to enjoy the cold like in the north of Vietnam. Yet, because the diurnal temperature range is low, climate in this region is quite similar over the months in year.