A cold front will sweep through the northern region on November 19-20 and will then affect the central region, said the National Centre for Hydro-Meteorological Forecasting.
Temperatures in the northern region may change a little during the daytime at around 20-21oC, but drop to 13-15oC at night.
In some mountainous areas, the temperature may fall to around 0oC. Chilly cold and extreme cold with fog and ice may appear in the region from November 21-24.
The cold spell will cause strong winds and rough seas in the Bac Bo (Tonkin) Gulf.