The temperature of the cosmic microwave background radiation has been measured at wavelengths of 0.33, 3.0, 8.2, and 21.3 cm. These measurements represent a continuation of the work reported in 1985 by Smoot et al. The new results have a weighted average of 2.70 + or - 0.05 K and are consistent with past measurements. They limit the possible distortion of the cosmic microwave background radiation spectrum to less than 6 percent. The results of all measurements to date are consistent with a Planckian spectrum with temperature 2.74 + or - 0.02 K spanning a wavelength range of 0.l-50 cm.