The factor in the atmosphere that is most responsible for changes in an area's temperatures and humidity levels is air pressure. Changes in air pressure can lead to changes in temperature and humidity. When air pressure is high, it tends to bring clear skies, cooler temperatures, and lower humidity levels. On the other hand, when air pressure is low, it tends to bring cloudy skies, warmer temperatures, and higher humidity levels. Air pressure variations can be influenced by factors such as the movement of air masses, the presence of weather systems, and topography.
