What does atmospheric pressure primarily depend on?

The primary factor that influences atmospheric pressure is altitude. As you ascend in altitude, the weight of the air above you decreases, leading to a reduction in atmospheric pressure. This is because air has mass and exerts pressure due to the gravitational pull acting on it. At higher elevations, there are fewer air molecules above to exert pressure on those below, resulting in lower atmospheric pressure.

In contrast, while weather patterns, humidity levels, and temperature conditions can influence local atmospheric pressure changes, they do not fundamentally determine the baseline pressure experienced at a given location. Weather patterns can lead to fluctuations in pressure due to the movement of air masses, humidity can affect air density but does not directly change the overall atmospheric pressure, and temperature does influence air density, yet the essential relationship between altitude and pressure remains the dominant factor in understanding atmospheric pressure dynamics.