What is humidity?

Humidity is how much water vapor is floating around in the air.

Imagine you're playing with a sponge in the bathtub. When the sponge is all wet and squishy, it holds a lot of water, that’s like high humidity. But when you squeeze out most of the water and the sponge feels dry, that’s like low humidity.

The air around us can act like a sponge too! When it's warm, the air can hold more water vapor, just like a wet sponge holds more water. When it gets cooler, the air can’t hold as much, and sometimes that extra water vapor turns into drops of water, like when you see mist on your bathroom mirror in the morning.

If you've ever felt sticky after swimming on a hot day or noticed your hair frizzing up in the summer, that’s humidity at work. It's just the air doing its sponge thing, holding onto water and making everything feel more moist or dry, depending on how full it is.