Variation of barometer with weather

Winter is dry and cold, the air density is higher than that in summer, and the water vapor content is lower than that in summer, thus making the oxygen concentration higher than that in summer. So the air pressure in winter is higher than that in summer; The water vapor content in the air on sunny days is much less than that on cloudy days, and the relative oxygen concentration is higher, so the air pressure is higher than that on cloudy days. We feel chest tightness on cloudy days, because our lungs need to expand so much that the air pressure in the lungs is lower than the outside air pressure to let air into the lungs. Considering the state of water, the air is dry in winter and sunny days. At this time, most of the water exists in gaseous state. If the content of water vapor in the same air is high, the total amount of gas will be high, so the air pressure will be high. Similarly, the air humidity is high in summer and cloudy days, that is to say, there are many small water droplets in the air, and most of the water exists in the air in liquid state, so the total amount of gas is bound to be much less, so the air pressure is relatively low.