Can water evaporate below 100C?

Yes, Water Can Evaporate Well Below 100°C

You don’t need boiling water to see evaporation in action. In fact, water evaporates all the time—right at room temperature. The common misconception is that water only turns to vapor at 100°C, but that’s just the boiling point, where evaporation happens rapidly throughout the liquid. True evaporation, however, is a much quieter, constant process.

At the surface of any body of water—whether it’s a puddle, a glass, or a damp towel—some H2O molecules have enough kinetic energy to break free from the others. Even at cool temperatures, a small fraction of these molecules move fast enough to escape into the air as vapor. This is due to the natural distribution of molecular speeds: while most molecules move slowly, some zip around faster, gaining enough energy to overcome the weak hydrogen bonds holding them to the liquid.

This is why wet clothes dry overnight, even without heat. Humidity, airflow, and surface area all influence how quickly this happens—but temperature isn’t the only factor. On a cold, dry winter day, water still evaporates because the air can absorb moisture, and the active molecules keep escaping.

The process continues until equilibrium is reached—when as many molecules return to the liquid as leave it. But as long as the air isn’t saturated, evaporation wins. So yes, water absolutely evaporates below 100°C. In fact, it’s happening right now, wherever there’s moisture and air.