Two tourists wear traditional Chinese costumes to pose for pictures in Jingshan Park in Beijing on Sunday. The Forbidden City behind them is wrapped by heavy smog. Photo: Xinhua

Beijing has seen more smog in September due to a lack of the flow of cold air that prevents pollutants from dispersing, a meteorologist said at a press conference in Beijing on Sunday.

After autumn arrived in Beijing, the steady temperature and humidity has contributed to the smog, claimed Kang Zhiming, a senior engineer with the National Meteorological Center, at the press conference held by the China Meteorological Administration.

Kang said that there was little cold air or wind, making it difficult for pollution to disperse.

However, environmental experts insist that pollutants discharged by human activities contribute more to Beijing's smoggy weather.

"The climatic conditions in Beijing are similar every year, but the number of particles in the air has increased every year due to excessive emissions by human activity," Zhao Zhangyuan, a researcher with the Chinese Research Academy of Environmental Sciences, told the Global Times on Sunday.

Another reason for the smog is that Beijing's neighboring areas including Tianjin Municipality and Hebei Province have established many large-scale chemical and steel companies which consume large amounts of coal, resulting in heavy pollution in these areas, Ma Jun, director of the Institute of Public and Environmental Affairs in Beijing, told the Global Times.

As of 8 am on Sunday, 24 out of 35 monitoring spots in the capital recorded heavy air pollution. And the density of airborne particles measuring less than 2.5 microns in diameter, or PM2.5, exceeded 200 micrograms per cubic meter, according to the Beijing Municipal Environmental Monitoring Center, the Xinhua News Agency reported on Sunday.

In September, many areas across the country including Beijing, Tianjin, and Hebei, Shanxi and Jiangsu saw smog for more than five days. Shanxi, Henan and Jiangsu provinces have had as many as 10 to 15 days of smog, Chen Zhenlin, speaksperson of the China Meteorological Administration, said at the conference.

By Sunday, Beijing had experienced 15 days of smog in September, about 11 days more than the same period in previous years.

During the national holidays, most areas of the country may see fair weather and mild temperature. Meanwhile, Southwest China and South China will see more rainfall. In the later period of the holidays, smog will hit some areas, Chen said.