What can slightly cause variations in atmospheric pressure?

Altitude and temperature indeed play significant roles in influencing atmospheric pressure. As altitude increases, the density of the atmosphere decreases. This relationship means that atmospheric pressure is lower at higher elevations compared to sea level because there is less air above pressing down.

Temperature also affects atmospheric pressure because warmer air is less dense than cooler air. When air heats up, it expands and can rise, leading to a decrease in pressure at the surface. Conversely, cooler air is denser, contributing to higher atmospheric pressure.

The interplay between altitude and temperature means that atmospheric pressure isn't uniform; it can vary based on where you are and the prevailing weather conditions. This is why altitude and temperature are recognized as key factors that can cause variations in atmospheric pressure.

While wind speed, humidity levels, and time of day can have an impact on weather conditions, they are not as directly tied to the fundamental changes in atmospheric pressure as altitude and temperature are. Wind speed primarily describes the movement of air masses rather than affecting the overall pressure directly. Similarly, while humidity can influence air density, its effects are secondary compared to the primary influences of altitude and temperature. Time of day can cause temperature changes, but it does not independently cause significant variations in atmospheric pressure.