Approved by the municipal government, the red alert will be activated 8 PM local time tomorrow and is expected to be lifted on December 21 when the air quality in the city improves, state-run Xinhua news agency reported.
China National Environmental Monitoring Centre said during the period, Beijing and neighbouring Tianjin Municipality and Hebei Province will suffer heavy air pollution, which will also affect Shandong and Henan provinces.
Construction sites will be shut down, certain factories closed and schools advised to suspend classes during the red alert.
According to an updated emergency response plan for severe air pollution released November, four consecutive days of heavy air pollution, including two days of severe air pollution, activate a red alert.
A red alert is also issued if the city's Air Quality Index (AQI) reaches 500.