How slowly does water evaporate?

How Fast Does Water Actually Evaporate?

When you leave a glass of water sitting out on a counter, you might not notice anything happening right away. In reality, a constant, silent process is taking place. Liquid water is slowly turning into invisible water vapor and escaping into the surrounding air.

If you were to place that glass on a sensitive digital scale, you would actually see the numbers tick down. On average, water loses about .0001 grams every single second under normal room conditions. While that amount sounds microscopic, it adds up steadily over the course of the day.

To put that speed into perspective, it takes roughly 16 minutes for just a single tiny drop of water to vanish completely into thin air. Of course, this rate isn't set in stone. Factors like room temperature, humidity, airflow, and the surface area of the container can speed up or slow down how fast the water molecules break free.