What is relative humidity?

Relative humidity is defined as the amount of water vapor present in the air relative to the maximum amount of water vapor that the air can hold at a specific temperature and pressure. This concept is crucial in meteorology because it helps determine how humid or dry the air feels, which is a significant factor in weather conditions, cloud formation, and precipitation.

When the air is saturated, it has reached its maximum capacity for moisture at that temperature, resulting in a relative humidity of 100%. Conversely, lower relative humidity indicates that the air can still hold more moisture. Understanding this relationship is vital for pilots as it can affect flight operations, visibility, and the likelihood of weather phenomena such as fog, clouds, and thunderstorms.