Heavy snowfall caused a traffic jam that extended nearly 5 km on the top of O Quy Ho mountain pass in Sa Pa town in the northern province of Lao Cai on Sunday morning.
Many roads and trees have been blanketed by 5 to 10cm thick snow.
Local people said the snow started falling at 9:30am on December 15 in the Xe mountain area at an altitude of 2,200m.
Nguyen Phuc Thanh, a forest official in charge of managing the Nui Xe mountain area, said that as of 9:30 am today the temperature in O Quy Ho fell to about 2 degree Celsius while the temperature in the Nui Xe Mt area was under 0 degree Celsius.
He added that the temperatures continued to fall as of 11:30am.