What does relative humidity represent?

Relative humidity represents the ratio of the actual amount of water vapor present in the air to the maximum amount of water vapor that the air can hold at a given temperature, expressed as a percentage. This measurement is crucial in understanding how comfortable or clammy the air feels. When relative humidity is at 100%, the air is fully saturated with moisture, and any additional water vapor will result in condensation, such as fog or rain.

Understanding relative humidity is essential for various applications in aviation, as it affects aircraft performance, weather prediction, and overall comfort levels for passengers and crew. It influences factors such as visibility, lift, and engine performance. The other choices reflect different aspects of moisture in the atmosphere but do not accurately describe relative humidity.