Beijing enjoyed largely clear skies in November, according to the latest official data.
The Ministry of Environmental Protection reported on Thursday that 80 percent of days in November had good air quality, up from 43.3 percent in the same period last year.
Good days are those on which the AQI is lower than 100.
The average concentration of PM2.5 — hazardous fine particulate matter — also fell by 54 percent compared with November 2016, down to 46 micrograms per cubic meter, the ministry data show.
In the first 11 months of this year, the capital saw blue-sky days 60.2 percent of the time.