Temperatures are expected to fall sharply from January 15.
In the high mountains, the mercury could fall to as low as 3C, with snow flurry and frost likely to appear, according to the national weather service.
After hitting the northern region, the cold air will continue moving southwards, causing temperatures in the north-central region to drop to around 11-14C, while temperatures in the region from Quang Binh to Thua Thien Hue are expected to fall to 14-17C.
From late January 14 to January 15, the cold spell is forecast to bring showers in the northern region, Thanh Hoa and Nghe An, while showers and medium to heavy rains are likely to affect parts of the region from Ha Tinh to Quang Ngai.