What is relative humidity?

Relative humidity is defined as the percentage of water vapor in the air compared to the maximum amount of water vapor that the air can hold at a given temperature. This concept is crucial in meteorology, as it helps to indicate how saturated the air is with moisture. When the air reaches a relative humidity of 100%, it is fully saturated, and this is when condensation can occur, leading to phenomena such as fog, dew, or precipitation.

Understanding relative humidity is important for predicting weather patterns, as high humidity levels can influence temperature and can also affect the comfort level of individuals in that environment. It is a key measure in assessing atmospheric conditions for pilots, especially when evaluating potential turbulence or cloud formation.

The other choices refer to different aspects of humidity measurement but do not correctly define relative humidity. Absolute humidity measures the actual water vapor content in the air, while the mixing ratio focuses on the mass of water vapor relative to dry air. The ratio of absolute humidity to total air pressure also does not accurately represent relative humidity as it lacks the necessary comparison to saturation.