The boiling point of water is 100°C (212°F) at standard atmospheric pressure, which is defined as 1 atmosphere (atm) or 101.3 kilopascals (kPa) at sea level.

At this temperature, the vapor pressure of water equals the surrounding atmospheric pressure, allowing water molecules to escape from the liquid into the gas phase. This is the point at which rapid vaporization (boiling) occurs throughout the liquid, not just at the surface.

However, the boiling point is not fixed—it changes with pressure. At higher altitudes, where atmospheric pressure is lower, water boils at a lower temperature. In a pressure cooker, the pressure is increased, so water boils at a higher temperature, which cooks food faster.

Understanding boiling point is crucial in cooking, meteorology, engineering, and even in biology, where organisms adapt to environments with different pressures and temperatures.