Annual Air Quality Index (AQI) of 367 Chinese Cities (2014–2024)

The Air Quality Index (AQI) is a comprehensive indicator used to assess air pollution levels, based on the concentrations of six major pollutants: PM2.5, PM10, SO₂, NO₂, O₃, and CO, with threshold values determined by the GB3095-2012 national standard. The AQI classification is as follows: Excellent (AQI ≤ 50), Good (AQI ≤ 100), Light Pollution (AQI ≤ 150), Moderate Pollution (AQI ≤ 200), Heavy Pollution (AQI ≤ 300), and Severe Pollution (AQI > 300). Using real-time monitoring data from air quality stations across China from 2014 to 2024, the AQI for each city is calculated by first determining the daily average AQI based on monitoring stations within the city, then computing the annual average AQI, and finally aggregating the annual average AQI values for 367 cities, providing a comprehensive analysis of air quality trends over the decade.