Science explained

How clouds form

Clouds form when moist air reaches conditions where water vapour can condense onto tiny particles or freeze into ice crystals.

WeatherClouds

Editorial review: August 12, 2026 · Julian E. Marston

Air must become saturated enough

Cooling, adding moisture or mixing air masses can bring air toward saturation.

Cloud condensation nuclei matter

Tiny airborne particles provide surfaces on which droplets can form.

Rising air often cools

Expansion at lower pressure can lower an air parcel's temperature.

Cloud type reflects motion and stability

Layered and vertically growing clouds reveal different atmospheric structures.

This page explains scientific concepts for general learning. It does not replace laboratory safety procedures, professional engineering guidance, or individualized medical advice.