According to the national weather agency, the cold air already affected the northern area of the north-central region and parts of the northwest region on the morning of December 1.
Lang Son’s weather station reported that the temperature in Mount Mau Son dropped to 4.5C as of 7am on December 1.
The cold air will continue spreading to other parts of the northwest, north-central and central-central regions later in the day.
During the cold spell, the temperatures will be the lowest in northern mountainous and midland regions, averaging at 8-11 degrees.
Temperatures in the Red River Delta hover around 11-13C while the provinces from Thanh Hoa to Quang Binh will see mercury levels at 14-17C.