There is not much to do in Dong Hoi but relax, enjoy its beaches and drink a beer; get there now before the masses do. Many hotels and tour groups operate tours to these nearby beaches and caves. There are few tourists in Dong Hoi, so you will be greeted with many hellos. Nhat Le Beach is nearby, but the focus of the town is very much on the river and canals.
Dong Hoi had been a small village before Vietnam was divided during the time of the Trinh-Nguyen War (1558–1775), after which Vietnam was divided into two countries: Dang Trong (south) and Dang Ngoai (north) with the Gianh River as the frontier. Dong Hoi was an important fortress of the southern Nguyễn Lords. The Đồng Hới Wall was considered the barrier which protected the Nguyễn Lords from the attack by northern Trịnh family. The site of Dong Hoi today is just south of this boundary.
During the Indochina War (between the French and the Viet Minh in 1950s, the Đồng Hới airbase was used by the French to attack both the Viet Minh in north-central Vietnam and the Laotian Pathet Lao Army in central and southern Laos. During the Vietnam War, Đồng Hới was heavily devastated by bombardments from US B-52s due to its location near the seventeenth parallel and the demilitarized zone between North and South Vietnam. The city was almost leveled and was rebuilt slowly after the war ended in 1975. The town was planned and rebuilt on a large scale especially after 1990 when it became the provincial capital.
There are four distinct seasons in Đồng Hới. In the spring, it is cool, humid and foggy. The average annual temperature is 24.4°C, average rainfall varies from 1,300 to 4,000 mm, total sunshine hours per year is 1,786 hours, average annual moisture is around 84%. The city has a monsoon climate with three types of wind: southeast wind, southwest wind, and northeast wind.
It is rainy in the fall but the weather is comfortable with the temperature being 26-31°C. In the winter, due to the northeast wind blowing from the Chinese mainland, the temperature may go down below -18°C, and there may be slight rain. The highest precipitation gets highest level in August (118.4 mm), compared to just 38.9 mm in January. The best time to visit this city is from April to September when it’s cool enough to go swimming.