What happens to humidity as temperature decreases?

When temperature decreases, the air's capacity to hold moisture also decreases. Humidity refers to the amount of water vapor present in the air. Cooler air can hold less moisture than warmer air, which means that as the temperature drops, the relative humidity can increase even if the absolute amount of moisture in the air remains the same.

As the air cools, if the moisture content does not change, the relative humidity increases because relative humidity is a measure of the current moisture level in relation to the maximum moisture level possible at that temperature. If the air cools sufficiently, it can also reach saturation, leading to condensation of water vapor and the formation of dew or frost. This interplay between temperature and humidity is critical in understanding weather patterns and the behavior of moisture in the atmosphere.