Clear and blue sky in Beijing on Dec 2, 2015. [Photo/IC]

Beijing suffered the year's most severe pollution as it was shrouded in smog from Friday until late Tuesday night. A westerly wind swept through the city at midnight Tuesday, blowing away heavy pollution so that by this morning, Beijing woke up to a beautiful blue sky. According to local authorities, the orange pollution alert issued earlier has been lifted and the clear skies are expected to persist until Friday.