Relative humidity is a measure of how much moisture is in the air compared to the maximum amount of moisture the air can hold at a specific temperature. It is expressed as a percentage. For example, if the relative humidity is 50%, the air is holding half of the moisture it could potentially hold at that temperature. High relative humidity can make the air feel warmer and more uncomfortable, while low relative humidity can lead to dry skin and respiratory issues. Weather reports often include relative humidity to help people understand how the weather might feel, especially in relation to temperature and comfort.