Question

how does water Vapour affect air pressure​

Answer 1

Answer:

Since water vapor is less dense than dry air if both have the same temperature, the addition of water vapor decreases the overall density of the air and lowers its pressure

Answer 2

As humidity increases pressure decreases. Since water vapor is less dense than dry air if both have the same temperature, the addition of water vapor decreases the overall density of the air and lowers its pressure.