As the temperature increases and the amount of water vapor in a piece of air remains constant, what happens to the relative humidity?

Arab Weather - When the temperature rises and the amount of water vapor in a piece of air remains constant, the relative humidity decreases.

Relative humidity depends on both temperature and the amount of water vapor present in the air. As the temperature increases, the air's ability to hold water vapor increases, reducing the ratio of existing water vapor to the amount the air can hold at the new temperature, and thus the relative humidity decreases.