Heavy smog shrouded Beijing on Friday morning, with the city's weather department advising locals not to set off fireworks during Lantern Festival. At 9 a.m., the air quality index (AQI) at stations in urban Beijing reached Level 5 between 246 to 287, or heavily polluted, according to the Beijing Municipal Environmental Monitoring Center's website. Lantern Festival, which brings an end to the Spring Festival season, or Chinese Lunar New Year, is on the 15th day of the first month of the Chinese lunar calendar. On this day, Chinese people set off fireworks, watch lantern shows and enjoy the first full moon of the new lunar year. However, weather forecasters said it would be difficult to see the moon in Beijing on Friday because of the smoggy weather.