Relative humidity is a measure of the amount of moisture 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 air can hold 10 grams of water vapor at a certain temperature and it currently holds 5 grams, the relative humidity would be 50%. 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 precipitation.