The temperature at which a solid transforms into a liquid under atmospheric pressure is known as a solid's melting point. Ice melts at 1 atmosphere of pressure, which is very near to 0 degrees Celsius.
The freezing point or crystallization point is the temperature at which a liquid changes back to a solid. The freezing and melting points of a number of substances coincide.

It is known that ice starts melting at $0°\mathrm{C}$.

Now to convert temperature from degree Celsius to degree kelvin, add 273.15 to the given temperature in degrees Celsius. Thus.,

$0°\mathrm{C} = 0 + 273.15 = 273.15 \mathrm{K}$

Hence. the melting point of ice is 273.15  Kelvin.