Sapa is experiencing the peak of its rainy season. There are, however, some beautiful sunny days when temperatures hit 23°C (74°F).
The whole region is put in danger of some little typhoons. Hue and Hoian are still terribly dry and hot. Temperatures may peak up to 38°C (100°F). Nha Trang also records its year-high temperature of 32°C (92°F) in this month.
Ho Chi Minh City and Can Tho observe a slight reduction of both rainfall and temperatures.
note: this forecast for Vietnam weather in August was drawn from August of previous years.
August is still in low season so reservations are not necessary.
You may save a bit to travel in August, as prices are quite low in comparison to other months.