BEIJING — Beijing and surrounding areas reported good air quality on more days in October thanks to strengthened efforts to reduce emissions.

In 13 cities in the Beijing-Tianjin-Hebei region, “good air” days accounted for 69.2 percent on average last month, up by nearly 5 percent from a year ago, the Ministry of Environmental Protection (MEP) said on Nov 17. Beijing saw the biggest improvement as its ratio of days with blue skies reaching 80 percent.

The density of PM2.5 dropped 10.3 percent from a year ago in those cities, and the density of PM10 went down by 15.7 percent.

Air quality usually worsens in winter in northern China where less wind and coal-powered heating combine to exacerbate air pollution.

The improvement was attributed to government measures to tackle air pollution, with dirtier coal-powered heating being replaced and industrial polluters strictly penalized. Special inspection teams have also been dispatched to cities.

However, Beijing and nearby areas are still not free from concern. Air quality actually worsened in the first ten months and was still lower than the national average. The region contributed half of the top-ten list of cities with the worst air quality across the country.

Nationwide, the 338 cities monitored by the MEP reported good air quality on 87.8 percent of the days in October, down by 5 percentage points from the same period last year.

The ratio was 93.8 percent in the city cluster around Yangtze River Delta and 73.1 percent in cities around Pear River Delta.