Humidity is the amount of water vapor in the air. Water vapor is a type of gas made up of tiny water droplets. The air can hold different amounts of water vapor depending on the temperature. When the air is warmer, it can hold more water
vapor. When the air is cooler, it holds less.
When the air has a lot of water vapor in it, we say it is humid. When it has less, we say the air is dry. Humidity can affect how we feel: when the air is humid, it can feel sticky and muggy. When the air is dry, it feels more comfortable.
We measure humidity with a special instrument called a hygrometer. It measures the amount of water vapor in the air and tells us the humidity level. We usually describe humidity as a percentage, with 100% being very humid and 0% being completely dry.
