Beijingers are to be warned of "haze" in daily weather forecasts so they can take measures to avoid air pollution.

The municipal meteorological authorities are to include haze levels on hazy days when the humidity is under or at 80 percent from February 1.

Haze would be divided into three grades -- light, moderate and heavy, said Guo Hu, head of the Beijing Municipal Meteorological Station.

Light would be defined as visibility between five and 10 kilometers; moderate with visibility between two and five kilometers; and heavy haze means visibility under two kilometers.

Guo said haze formed when the concentration of dust, smog and other harmful matter was high in the air during days without wind.

Experts warn that haze contains substances harmful to the respiratory tract and lungs. The public is recommended to stay indoors during moderate and heavy haze days.

Beijing reported 10 haze days in December, or one-third of the total recorded in the capital last year.

Shi Hanmin, head of Beijing Municipal Environmental Protection Bureau, said last week that local environmental authorities would take further steps to control air pollution and had set an ambitious target of 245 "blue sky" days this year after beating the 2006 goal.

The authorities reported the annual target of 238 days with fairly good air quality had been reached on December 24, and recorded three more such days before the New Year.

Experts said rain in July and August led to the record number of good air quality days.

Du Shaozhong, deputy director of the bureau, attributed the achievement partly to intensified efforts made by environmental protection agencies in reducing pollution from coal burning.

According to the bureau's website, the municipal government will put air quality improvement, the public's biggest concern, on top of its agenda this year.

Beijing launched the "Defending the Blue Sky" program in 1998, when the city had only about 100 days of "blue sky" a year.