According to the National Centre for Hydro-Meteorological Forecasting, temperatures are expected to fall by around 3-4 degrees Celsius as unsettled weather develops towards the end of October.
In northern Vietnam, scattered showers and thunderstorms are forecast from the night of October 26 to October 29.
Central areas from Thanh Hoa to Hue are expected to see showers and thunderstorms over the same period, with locally heavy rain.
The northern part of the south-central coast is forecast to experience similar conditions from October 27 to 29, followed by scattered showers until around October 31.
Southern Vietnam could also see scattered afternoon and evening showers and thunderstorms on October 28 and 29.
On October 25, temperatures across northern Vietnam ranged from 23 to 34 degrees Celsius, with cooler conditions in mountainous areas.
Hanoi was forecast to have daytime sunshine and isolated overnight showers, with temperatures between 25 and 34 degrees Celsius. Ho Chi Minh City was expected to see sunshine followed by evening thunderstorms, with temperatures ranging from 25 to 34 degrees Celsius.
Looking ahead to November 20, forecasters expect fewer storms and tropical depressions over the East Sea than the long-term average for the period.
Widespread rain remains possible across Vietnam, with moderate to heavy rainfall most likely in central areas. Cold air outbreaks affecting northern and central Vietnam are also expected to be weaker than usual.