Why is the air quality in Beijing so bad?

Heavy pollution, too many vehicles and too much tail gas emissions are not conducive to the diffusion of pollutants in winter. The climate in Beijing is a typical semi-humid continental monsoon climate in the north temperate zone, with high temperature and rainy summer, cold and dry winter and short spring and autumn. The frost-free period of the whole year is 18 ~ 2 days, and the western mountainous area is shorter. In 27, the average rainfall was 483.9 mm, which was one of the most rainy areas in North China. The seasonal distribution of precipitation is very uneven. 8% of the annual precipitation is concentrated in June, July and August in summer, with heavy rain in July and August.

the annual average solar radiation in Beijing is 112 ~ 136 kcal/cm. The two high-value areas are distributed in Yanqing basin and the northwest of Miyun county to the east of Huairou, with annual radiation above 135 kcal/cm. The low-value area is located near Xiayunling in Fangshan District, with an annual radiation of 112 kcal/cm. The average annual sunshine hours in Beijing are between 2 and 28 hours. The maximum value is more than 28 hours in Yanqing District and Gubeikou, and the minimum value is distributed in Xiayunling, with sunshine of 263 hours. In the rainy season in summer, the sunshine hours are reduced, and the monthly sunshine is about 23 hours; Although the sunshine hours in autumn are not as much as those in spring, they are more than those in summer, with a monthly sunshine of 23-245 hours. Winter is the season with the least sunshine hours in a year, and the monthly sunshine is less than 2 hours, generally 17 ~ 19 hours.

Because the climate in Beijing and Guangzhou is different, Beijing has a typical warm temperate and semi-humid continental monsoon climate, with high temperature and rainy summer, cold and dry winter and short spring and autumn. Guangzhou is located in the south subtropical monsoon climate zone, and its climate features are: high temperature, more precipitation, less frosty days, more sunshine, low wind speed and frequent thunderstorms. The high temperature: the annual average temperature is 21.9℃. Because of the different geographical locations, the weather between Beijing and Guangzhou is quite different.