When is the time of day when the air in Beijing is the worst?

Around 7 o'clock in the morning.

According to the Beijing Environmental Protection Bureau, the worst air quality of the day is around 7 a.m. in the morning. Because all living things before this only require oxygen and lack replenishment, there is a lot of carbon dioxide and harmful gases in the air.

Beijing has the lowest air pressure on cloudy days in July, because the temperature in summer is high, the air density is low, and the air pressure is also low. In winter, the temperature is low, the air density is high, and the air pressure is high.