Air’s capacity to hold moisture is temperature-dependent; warmer air can hold significantly more water vapor than cooler air. As temperatures decrease, the air becomes saturated more easily, causing the relative amount of moisture in the air, expressed as a percentage, to increase. This phenomenon directly contributes to the noticeable rise in atmospheric moisture levels during the nighttime hours.
Understanding nocturnal humidity variations is crucial for various applications, including agriculture, weather forecasting, and even human health. High atmospheric moisture content can influence dew formation, which is essential for some plant species, while also impacting the severity of fog and the comfort level of individuals. Historical observations of this daily cycle have long been used to predict early morning weather conditions.