A thick wall of fog rolls onto an airstrip at Kunming Changshui International Airport in Kunming, Yunnan Province on February 18. The dense fog dissipated after a half hour and caused no flight delays. Photo: yunnan.cn

According to meteorologists, the fog was a result of warm and cold air fronts colliding in a small area. Kunming has recently experienced a stint of cloudy and rainy weather. Photo: yunnan.cn

Photo: yunnan.cn

Photo: yunnan.cn