Pressure melting point
![In this log-lin pressure-temperature phase diagram of water, the pressure melting point for a given pressure lies along the black line rising from the solid/liquid/vapour triple point along the 0°C vertical line.](/Images/godic/202502/04/Phase_diagram_of_water.svg2956.png")
The pressure melting point is the temperature at which ice melts at a given pressure. The pressure melting point is a constant 0°C at pressures above the triple point at 611.7 Pa, where water can exist in only the solid or liquid phases, through atmospheric pressure (100 kPa) until about 10 MPa. With increasing pressure above 10 MPa, the pressure melting point decreases to a minimum of -21.9°C at 209.9 MPa. Thereafter, the pressure melting point rises rapidly with pressure, passing back through 0°C at 632.4 MPa.