Water freezes at 0 degrees Celsius (°C). This temperature is a critical point in the study of thermodynamics, serving as the baseline for the Celsius temperature scale. At this point, the molecules in liquid water slow down significantly, rearranging themselves into a crystalline structure, which defines ice. The freezing point can be influenced by pressure; for instance, increased pressure can lower the freezing point of water slightly. Knowing this temperature is essential in meteorology, environmental science, and various everyday applications, such as cooking and freezing food.