Air pollution in Beijing, China is a serious issue, especially in winter and spring. The study looked at PM2.5 levels from 2013 to 2017 and found that pollution is worse in southern areas. Pollution levels fluctuate throughout the day, with peaks in the morning and evening. Local pollutants and pollutants from nearby cities like Langfang contribute to Beijing's pollution. Factors like wind speed and direction also play a role in pollution levels. Overall, air quality is better when the wind comes from the north.