Yes, air pressure does change with humidity, but the relationship is a bit nuanced. When humidity increases, the air contains more water vapor, which is less dense than the nitrogen and oxygen that make up most of the atmosphere. This means that as the amount of water vapor in the air increases, the overall density of the air decreases, leading to a reduction in air pressure.
To explain further, air is a mixture of gases, and when water vapor (which has a lower molecular weight compared to other gases in the air) takes the place of heavier molecules, the total weight of the air in a given volume decreases. Therefore, in areas with high humidity, you might notice lower air pressure readings compared to areas with low humidity. Conversely, dry air is denser and contributes to higher air pressure.
In summary, while humidity itself does not directly cause air pressure to rise or fall, it is an important factor that influences the density of air, which in turn affects air pressure. This interplay is crucial in meteorology and helps explain why weather systems behave the way they do.