supercooling

Supercooling occurs when pure water is cooled below its freezing point without turning into ice. This happens because, without impurities or disturbances, the water molecules remain in a liquid state even though they are colder than 0°C (32°F). When the supercooled water is gently disturbed or a small particle is introduced, it rapidly crystallizes into ice. This process shows that water can stay liquid below its freezing temperature if conditions are very controlled, but it's quite unstable and can change quickly with the slightest vibration or impurity.