Cold weather across the country has not only caused icy roads, but also fogged cities which have seen massive flight delays. The Chengdu Shuangliu International Airport in Southwest China's Sichuan Province was forced to shut down after a heavy fog hit the city on Sunday.

An airliner is grounded at Chengdu Shuangliu International Airport due to heavy fog in Chengdu, capital of southwest China's Sichuan Province, Jan. 6, 2013. [Xinhua]

The airport was closed since 4 am., delaying over 100 flights and stranding thousands of travellers. To avoid further stranding, operators of the airport have sent out early warning signals of possible delays. The meteorological observatory of Chengdu issued an orange alert for heavy fog early Sunday morning.

According to a CCTV reporter at the airport, the outdoor temperature there reached minus 2 degrees Celsius in the morning, and thick fog dropped visibility to less than 100 meters. The fog didn't last long, and flights gradually resumed at 11:30am.