10月，168个重点城市中空气质量较好的前20位城市名单出炉！

Core Viewpoint - The air quality in China has shown significant improvement in October 2025, with reductions in various pollutants and an increase in the proportion of days with good air quality across major cities [1][3]. Overall Situation - The average PM2.5 concentration across 339 cities was 23.5 micrograms per cubic meter, a year-on-year decrease of 17.5% - PM10 averaged 39 micrograms per cubic meter, down 18.8% year-on-year - O3 averaged 103 micrograms per cubic meter, a decrease of 16.9% - SO2 averaged 7 micrograms per cubic meter, down 12.5% - NO2 averaged 18 micrograms per cubic meter, a reduction of 18.2% - CO remained stable at 0.8 milligrams per cubic meter - The proportion of days with good air quality was 96.2%, an increase of 3.9 percentage points year-on-year, while days with heavy pollution were 0.3%, up 0.1 percentage points [3]. Key Regions Beijing-Tianjin-Hebei and Surrounding Areas - PM2.5 concentration was 34.7 micrograms per cubic meter, down 37.1% year-on-year - O3 concentration was 104 micrograms per cubic meter, down 30.7% - The proportion of good air quality days was 88.8%, an increase of 19.0 percentage points - No days of heavy pollution were reported [8]. Yangtze River Delta - PM2.5 concentration was 23.2 micrograms per cubic meter, down 16.2% year-on-year - O3 concentration was 124 micrograms per cubic meter, down 10.8% - The proportion of good air quality days was 96.7%, an increase of 3.8 percentage points [9]. Fenwei Plain - PM2.5 concentration was 28.9 micrograms per cubic meter, down 33.7% year-on-year - O3 concentration was 91 micrograms per cubic meter, down 34.1% - The proportion of good air quality days was 96.5%, an increase of 8.4 percentage points [10]. Key Cities - Among 168 key cities, the top 20 cities with the best air quality included Guiyang, Kunming, and Suining, while the bottom 20 cities with the worst air quality included Baoding, Shijiazhuang, and Tianjin - The cities with the lowest PM2.5 concentrations were Lhasa, Zhoushan, and Suining, while those with the highest concentrations included Baoding, Handan, and Zhuzhou [12].