Photo shows a snow-covered building on a mountain in Lhasa, capital of southwest China's Tibet Autonomous Region, Dec. 19, 2018. Lhasa witnessed the first snow this winter on Tuesday. (Xinhua/Chogo)

Photo shows the snow-covered Potala Palace in Lhasa, capital of southwest China's Tibet Autonomous Region, Dec. 19, 2018. Lhasa witnessed the first snow this winter on Tuesday. (Xinhua/Purbu Zhaxi)

A woman poses for wedding photos at the snow-covered Potala Palace square in Lhasa, capital of southwest China's Tibet Autonomous Region, Dec. 19, 2018. Lhasa witnessed the first snow this winter on Tuesday. (Xinhua/Chogo)

Aerial photo shows the view of a snow-covered park in Lhasa, capital of southwest China's Tibet Autonomous Region, Dec. 19, 2018. Lhasa witnessed the first snow this winter on Tuesday. (Xinhua/Purbu Zhaxi)

A tourist takes photos at the snow-covered Potala Palace square in Lhasa, capital of southwest China's Tibet Autonomous Region, Dec. 19, 2018. Lhasa witnessed the first snow this winter on Tuesday. (Xinhua/Liu Dongjun)

Birds are seen at the snow-covered Potala Palace square in Lhasa, capital of southwest China's Tibet Autonomous Region, Dec. 19, 2018. Lhasa witnessed the first snow this winter on Tuesday. (Xinhua/Chogo)

Aerial photo shows the snow-covered Potala Palace in Lhasa, capital of southwest China's Tibet Autonomous Region, Dec. 19, 2018. Lhasa witnessed the first snow this winter on Tuesday. (Xinhua/Purbu Zhaxi)