Gas phase thermal conductivities for silane, dichlorosilane, trichlorosilane, tetrachlorosilane, and tetrafluorosilane are reported between 28 and 350 degrees C using a differential hot-wire technique with helium as the reference gas. Thermal conductivity data for argon and hydrogen are also determined over the entire temperature range to verify the experimental method used. The results are compared with the available literature data. The reproducibility of the values is within 4%.