In April, the average concentration of PM2.5 in 339 prefecture-level and above cities nationwide was 28.1 micrograms per cubic meter, down 0.4% year-on-year; the average concentration of PM10 was 56 micrograms per cubic meter, up 5.7% year-on-year; the average concentration of O3 was 144 micrograms per cubic meter, up 4.3% year-on-year; the average concentration of SO2 was 8 micrograms per cubic meter, flat year-on-year; the average concentration of NO2 was 19 micrograms per cubic meter, flat year-on-year; and the average concentration of CO was 0.8 milligrams per cubic meter, flat year-on-year.

In April, the average proportion of good air quality days in 339 prefectural-level and above cities nationwide was 83.1%, a year-on-year decrease of 6.7 percentage points; the average proportion of days with heavy and above pollution was 2.1%, a year-on-year increase of 0.9 percentage points. The average proportion of days exceeding the standard caused by dusty weather was 9.7%, of which the proportion of heavily and above polluted days was 2.1%.

Proportion of days at all levels in 339 cities at prefecture level and above nationwide in April 2025

List of top 20 and bottom 20 cities of 168 key cities in terms of air quality in April 2025

In April, among the 168 key cities: the top 20 cities with better air quality were, in order, Lhasa, Zhangjiakou, Haikou, Urumqi, Huangshan, Zhuhai, Zhongshan, Chengde, Huizhou, Shenzhen, Hohhot, Datong, Lishui, Zhoushan, Ya'an, Fuzhou, Chaoyang, Yichun, Guiyang, and Shuozhou; and the bottom 20 cities with worse air quality were, in order, Yangzhou, Changzhou, Zhenjiang, Huzhou, Tongling, and Harbin, Wuhan, Kaifeng, Xiangyang, Ezhou, Maanshan, Jingmen, Hebi, Taizhou, Tianjin, Linyi, Zhengzhou, Heze, Shanghai and Huanggang.

In April, among the 168 key cities: the top 20 cities with lower PM2.5 concentrations were, in order, Lhasa, Zhangjiakou, Urumqi, Haikou, Shenzhen, Chengde, Shuozhou, Zhongshan, Datong, Hohhot, Zhoushan, Zhuhai, Huizhou, Lvliang, Baotou, Jinzhong, Chaoyang, Qingdao, Xiamen and Dongguan; and the bottom 20 cities with higher PM2.5 concentrations were, in order, Harbin, Jingmen, Jingzhou, Zhenjiang, Zhuzhou, Xiangyang, Xiangtan, Huanggang, Yangzhou, Anyang, Suizhou, Heze, Changsha, Kaifeng, Huainan, Huaibei, Huaian, Changde, Ezhou and Chuzhou.

Source: Ministry of Ecology and Environment