Is the air pressure high or low on cloudy days?

Bottom, generally speaking, areas with high ground pressure are often sunny, and areas with low ground pressure are often rainy. The high atmospheric pressure and low atmospheric pressure mentioned here are relative, not the absolute value of atmospheric pressure. The area with higher atmospheric pressure than the surrounding area is called high atmospheric pressure area; The air pressure in a certain area is lower than the surrounding air pressure, which is called low pressure area.

On the same horizontal plane, if the air pressure distribution is uneven, the air will flow from the high pressure area to the low pressure area. Therefore, if the air pressure in a certain area is high, the air in that area will flow out horizontally. The air above the high pressure area will drop. Because the air pressure increases with the decrease of altitude, when the air at high altitude falls, the pressure is increased, the volume is decreased, the temperature is increased, and the condensate in the air evaporates and dissipates. Therefore, the high-pressure central area is not conducive to the formation of clouds and rain, and it is often sunny. If the air pressure in a certain area is low, the air in the surrounding area will flow into the area horizontally, which will cause the air in the area to rise, and the rising air will expand due to the pressure reduction, and the temperature will drop, and the water vapor in the air will condense, so the low-pressure central area is often rainy.