Beijing residents saw a return of "long-lost" blue skies yesterday, with air quality improving to levels labelled "good" by the US embassy after hitting hazardous levels on 20 days last month.
Still, concerns over the smog that had blanketed the capital, as well as nearby northern and eastern provinces, have prompted the Beijing authorities to ask residents to set off fewer fireworks during the Lunar New Year.
The concentration of PM2.5, fine air particles that pose the greatest health risk, was 14 micrograms per cubic metre at 9am, according to the embassy. The level near Tiananmen Square fell to four from an average of 100, Beijing's environmental monitoring centre said yesterday.
Every day in January, Peak readings from the US embassy exceeded the World Health Organisation's recommendation for daily exposure of no higher than 25. The daily average last month was 196 micrograms per cubic metre, with an intraday high of 886 on January 12.
The China Meteorological Administration said a cold spell bringing precipitation dissipated fog and haze on the mainland. "Beijing welcomed long-lost blue skies this morning," it said.
"The fog and haze that has persisted for days will end its domination of the central and eastern regions", which would see snow and rain over the weekend, it said.
From January 1 to 28, Beijing had 23 smoggy days, about 10 more than the same period over the past 10 years and the most since 1954, said Liang Xudong, head of the Beijing Urban Meteorology Institute.
Meanwhile, the Beijing office on fireworks yesterday called on residents to refrain from setting off fireworks during the Lunar New Year that starts on February 10, "in order to reduce emissions of pollutants", Xinhua reported.
After hours of fireworks during last year's holiday, the density of PM2.5 increased sharply to 1,593 micrograms per cubic metre in downtown Beijing, 1.5 times higher than the most polluted day so far in the capital.