Is it raining low or high?

It's low air pressure \x0d\ because the reason why you can't breathe is that the air pressure inside your body is high, so it's easy to exhale instead of inhale. \ x0d \ Remember that atmospheric pressure is related to temperature, and the higher the temperature, the greater the pressure. \ x0d \ In fact, the factors that affect the density are not only the temperature, but also the contents of different gases in the air. The density of water vapor is smaller than that of air, and the water vapor content is high in rainy days, so the air pressure is low. \ x0d \ x0d \ Question about the density of water vapor: \ x0d \ The relative molecular mass of water is 18, and the average relative molecular mass of air is about 29. The volume of gas is directly proportional to the number of molecules, and has little to do with the types of molecules, so the density ratio of water vapor to air is about 18:29.