Where Do Puddles Go When They Dry Up?
When we say that a puddle has dried up, we mean that the water in it has evaporated. When water is exposed to air, some of it changes to a gas called water vapor. The water vapor rises and mixes with other gases in the air. The warmer and drier the air, the faster the water evaporates.
You can’t see water evaporate because it is in the form of tiny particles called molecules. There is always some water vapor in the air. As water vapor rises and cools, it condenses and forms small water drops. We see great masses of these droplets as clouds.
You’ve all seen how hotter water will evaporate faster, but that’s not the only thing controlling evaporation. If there’s already a lot of water in the air, there won’t be much room for more, so evaporation is slowed down by high humidity. If the air isn’t moving very much around a puddle, the air closest the puddle will get more humid as water evaporates into it, and the puddle will evaporate more slowly.
If there’s wind blowing though, all the humid air will be swept away from the puddle, leaving less humid air for the puddle to evaporate into, and you’ll speed up the puddle’s evaporation.
A lot of water from puddles just soaks into the ground though and from there into nearby streams and rivers, so unless the puddle is on a waterproof surface, evaporation is not the only reason puddles eventually disappear!