Why do you feel sultry before the rainstorm in summer?

Before the summer rainstorm, people with low air pressure, high water content, low oxygen content and poor respiratory system are prone to chest tightness and shortness of breath.

Because there is a lot of water vapor in the air on rainy days or before it rains, the average molecular weight of air decreases, that is, the air density decreases, which leads to the decrease of air pressure. The higher the temperature, the greater the pressure drop in rainy days. Therefore, people will feel chest tightness before it rains in summer (people inhale the external atmospheric pressure, of course, the change of oxygen content in the air is also related).

Because of the high ground temperature, high temperature and low pressure can be formed at a certain height from the ground, and a large amount of water will evaporate from the ground under low pressure. Because heat is always transferred from high temperature to low temperature, when water vapor rises and meets cold air, it will exchange with the high and low pressure of high-altitude cold air. When the temperature drops sharply, the ground will form high temperature and low pressure, and a large amount of water vapor will evaporate from the ground, making people feel stuffy. The combination of high temperature and low pressure and cold air will form rain, which will reduce the surface temperature and evaporation when it falls to the ground. People think it's cool, too.

Summer precipitation is generally caused by cold air and warm and humid airflow, while sultry is the expression of the increase of water vapor and temperature in the atmosphere. This is also a precursor to summer thunderstorms. Most of the rainfall in summer is showers and thunderstorms. The conditions for its occurrence are fine weather in the early stage, high temperature in some areas and strong air convection, which makes a large number of hot and humid air rise sharply and form cumulonimbus clouds. At the same time, the hot air in the atmosphere increases and the water vapor is sufficient. Although the temperature does not change much at this time, there is too much water vapor in the atmosphere, which is easy to saturate, so the water on the ground is not easy to evaporate, and the sweat on the human body is not easy to evaporate, so it will feel very hot and uncomfortable.