A rare sandy snowstorm hit northwest China's Xinjiang Uygur autonomous region on Dec. 1 delaying flights at Urumqi Diwopu International Airport and leaving 4000 passengers stranded. Photo: VCG

Xinjiang Meteorological Station chief He Qing said the “yellow snow” was caused by a strong cold front which formed powerful winds that carried sand from around Xinjiang’s northern city of Karamay south. Photo: VCG

Traffic slowed to a standstill in Urumqi during the storm on Dec. 1. Meteorologists expected the harsh conditions to be concentrated in Xinjiang but said nearby regions might experience similar weather. Photo: VCG

A layer of sand could be seen deposited on the top of the white snow on Dec. 1. Photo: VCG 

Passengers were stranded in Urumqi Railway Station on Dec. 1 when the harsh weather interrupted train services. Photo: VCG 

A sanitation worker cleans up the sandy snow. Photo: VCG