A liquid is in equilibrium with its vapor at its boiling point. On an average the molecules in the two phases have equal :

Average kinetic energy $\left(ϵ\right)=\frac{3}{2}{k}_{B}T$, according to kinetic theory.
${\mathrm{k}}_{\mathrm{B}}$ is the Boltzmann constant in this scenario. Thus, the relationship between kinetic energy and temperature is direct.
The molecules in the two phases have the same kinetic energy when the liquid is at equilibrium with its vapour pressure at its boiling point, which is when the temperature is the same.