In addition to lower temperatures, later on November 18, the cold air will bring showers to Hanoi and across northern region.
The weather system will first affect mountainous provinces in the morning before moving south to the Red River Delta and the North Central region in the afternoon.
In Hanoi, the highest temperatures are expected at 23-26C while the lowest temperatures will be 16-19C.
The mercury could fall to below 15C at night in the mountainous regions.
Due to the cold air, the sea will be rough in the Gulf of Tonkin and the northern area of the East Sea, including the Hoang Sa (Paracel) archipelago, while the northeastern wind will strengthen to Beaufort force 6-7.