The average concentration of PM2.5 in Beijing was 46 micrograms per cubic meter in the first half of this year, down 13.2 percent year on year, the Beijing Municipal Ecological Bureau announced Tuesday.

The capital city saw 113 good air quality days in H1, or 62.4 percent of all days in the six-month period, and the share was 2.7 percentage points higher than the year-earlier level. The city also saw less heavy pollution days compared with the previous year, the bureau said.

The density of PM2.5 in the city's districts averaged from 38 to 50 micrograms per cubic meter in H1, according to the bureau.

The average concentration of PM2.5 in Beijing was 51 micrograms per cubic meter last year, down 12.1 percent year on year, according to the annual environment report published in May.

Beijing started to implement a three-year action plan to win the war against air pollution. It has taken actions to curb pollutants from diesel trucks, dust and volatile organic compounds.