Dr Jabbar,

As is the case for most materials, how the SHC varies with temperature depends strongly on the phase and actual temperature considered.

For example, solid water (ice Ih) has a reasonably good linear dependence with absolute temperature - this is not true for liquid water.

There are abundant data sets that describe this quality for solid, liquid, and gaseous water. What phase and regime is of interest to you?

This is a graph of Cp along isotherms based on the NBS/NRC 1984 steam formulation.