Forchheimer's equation, considered to be a nonlinear extension of the linear Darcy's law, applies to a broader range of velocities for flows through porous media. In this article, we examine sensitivity of the Forchheimer model to permeability kappa and a nonlinear coefficient beta, using both experimental and computational data for validation. In addition to the direct observations, we were able to identify the role of temperature which influences the model by means of viscosity and density of the fluid. To get a quantifiable answer, we introduce a sensitivity index. Our results reveal a significant impact of the temperature to the model behavior.