New measurements of the absolute temperature of the cosmic background radiation have been made at 12-cm wavelength (2.5 GHz). They are part of a multifrequency experiment and have been carried out in July 1982 from a high-altitude site (3800 m above sea level) using a liquid-helium cold load for comparison. We obtain a temperature for the cosmic background radiation at 12 cm of 2.62±0.25 K.

• Received 25 May 1983

DOI:https://doi.org/10.1103/PhysRevD.29.2686