What is atmospheric pressure primarily caused by?

Atmospheric pressure is primarily caused by the weight of air in the atmosphere. This is due to the fact that the Earth’s gravity pulls the air down, creating pressure from the weight of the air molecules that are above any point in the atmosphere. Every column of air in the atmosphere exerts pressure at the surface due to its mass; thus, more air above a location results in higher pressure.

While the movement of air (such as wind) can affect local pressure readings and variations in pressure systems, the fundamental cause of atmospheric pressure is the weight of the air itself. Temperature fluctuations and humidity levels can influence the density and behavior of air, affecting pressure indirectly, but they are not the primary cause of atmospheric pressure.