No "severe pollution" was reported in Beijing in May, and the air quality was better in the capital and its surrounding areas than in April.
Compared with the same month last year, Beijing and 12 neighboring cities had air quality that met the national standards on average 43.5 percent of the days, up 10.2 percentage points, according to the Ministry of Environment statistics on Wednesday. These cities still had substandard air quality on more than 15 days
Nationwide, 74 major cities had on average 66.3 percent of days that met the standards. The average PM2.5 density in all these cities decreased.
Eight cities reported 100 percent clean air last month, including Shenzhen, Haikou and Nanning.
China has revised air quality monitoring standards, adding indices for ozone, carbonic oxide and PM2.5. The standard was first rolled out in 74 cities, including Beijing, Chongqing, Shanghai and Tianjin, and all provincial capitals in late 2012. The standard is being expanded nationwide.