The temperature dependence of the localized magnetic mode associated with cobalt impurities in MnF2 has been studied by neutron inelastic scattering methods. The frequency of the localized mode, relative to its value at the lowest temperatures, falls with increasing temperature less rapidly than the sublattice magnetization and also less rapidly than the frequencies of the band modes in the doped crystal. The frequency of the local mode falls from 3.57±0.05(1012 Hz) at T/TN=0.06 to 3.12±0.13(1012 Hz) at T/TN=0.84. Results have also been obtained for the temperature dependence of the relative intensities of the neutron groups associated with the local and band modes. Molecular field calculations show that the cobalt ion produces an enhancement, at elevated temperatures, of the thermal average value of the spin on neighboring manganese ions over that in the pure material. This leads to a temperature dependence of the local modes smaller than that of the sublattice magnetization, as observed.