The city’s air pollution emergency response office issued on Tuesday the first yellow alert for this winter, which is the least severe one in its newly updated three-tier warning system. The red alert is still the highest in its color-coded warning system, followed by orange and yellow, which is issued when the AQI (Air Quality Index) is forecast to exceed 200 for more than two days in a row.
As of 12 p.m. local time, Beijing’s Environmental Protection Monitoring Centre reported the city’s average AQI have reached 311, a level deemed “hazardous” on most scales.
