Air quality in Chinese cities improved in November, data from the Ministry of Ecology and Environment showed Monday. For 339 cities monitored by the Ministry, the share of days with good air quality stood at 91.9 percent last month, up 3.8 percentage points, year on year. The average PM2.5 density, a key indicator of air pollution, dropped 5.6 percent year on year to 34 micrograms per cubic meter, and the average density of PM10 shrank 13.6 percent year on year to 57 micrograms per cubic meter. From January to November, the share of good air quality days in these 339 cities stood at 86.8 percent, edging down 0.8 percentage points from a year earlier. A key region for air quality improvement, the Beijing-Tianjin-Hebei region, along with the neighboring areas, saw its share of good air quality days increase one percentage point year on year to 68.3 percent last month.