evaporation

Evaporation is the slow, quiet escape of a liquid's particles into vapour, happening only at its exposed surface — and it can happen at any temperature, not just at the boiling point.

• A puddle disappearing on a sunny day or wet clothes drying on a line are both evaporation at work, well below 100°C.
• It's also why sweating cools you down: sweat evaporating off your skin carries heat away with it, leaving you feeling cooler.
• Compared to boiling, evaporation is much slower and only ever happens at the surface — boiling involves the whole liquid and only kicks in at one specific temperature.

Faster air movement or a larger exposed surface speeds evaporation up, which is one reason clothes dry faster on a windy day.