Why Do Drinking Glasses Sweat? | Science for Kids?

Drinking glasses sweat when they get cold and meet warm air, just like ice cream melting on a hot day.

When you put a cold glass on a warm table, the glass wants to stay cool, but the air around it is trying to make it warmer. The air can't just go through the glass, so it makes tiny drops of water, which look like sweat on the outside of the glass.

Imagine you're playing with ice cubes in a bowl on a sunny day. The ice melts into water because the warm air is giving its heat to the cold ice. That's what happens inside the glass, the cold glass takes some heat from the warm air, and that makes the air around it change into water droplets, just like when you see puddles after a rainstorm.

If you put a soda can in the fridge and then take it out on a hot day, it will get wet from the outside, that's sweating too! The same thing happens with your glass. It’s just like when you take a cold drink out of the fridge and see water droplets forming on the outside. Drinking glasses sweat when they get cold and meet warm air, just like ice cream melting on a hot day.

When you put a cold glass on a warm table, the glass wants to stay cool, but the air around it is trying to make it warmer. The air can't just go through the glass, so it makes tiny drops of water, which look like sweat on the outside of the glass.