BEIJING — Air quality in 338 Chinese cities improved year on year in August, with average PM2.5 density down, the Ministry of Environmental Protection (MEP) said on Sept 12.

The average density of PM2.5, fine particulate matter that causes smog, stood at 29 micrograms per cubic meter in August, down 14.7 percent from the same period last year.

In the Beijing-Tianjin-Hebei urban conglomerate the decline was 30.2 percent in August to a level of 37 micrograms per cubic meter.

In August, 338 cities enjoyed good air quality on 89.6 percent of days, an increase of 1.9 percentage points.

In the Beijing-Tianjin-Hebei region, the share of days with good air quality during the month stood at 83.6 percent, a year-on-year increase of 21.6 percentage points, according to the MEP.

The city of Haikou in Hainan province continued to have the cleanest air out of the nation’s 74 major cities, while Langfang in Hebei province was the worst polluted.

Hebei province had five of the 10 worst polluted cities in August.