According to details provided by the Lao Cai Hydrometeorological Station, the natural phenomenon tends to be caused by the extreme cold spell that has spread throughout northern and northcentral regions over recent days.

The station noted that when the sun came up and the temperature duly increased, the frost layer gradually melted away.

Meteorologists added that temperatures would likely continue to drop on November 21, with the phenomenon continuing to appear at the peak of Fansipan.

Source: VOV