The introduction reviews the geomagnetic disturbances due to high-speed solar wind streams produced by coronal holes and discusses the history of radio observations of coronal holes. In the main part of this work, using the central meridian column of the 9.1 cm Stanford solar radio maps, the authors constructed synoptic charts emphasizing temperatures near the quiet solar disk level. Synoptic charts were made for Carrington Rotations 1601-1605 May - August 1973 which represents the overlapping period from the commencement of solar X-Ray data from ATM - Skylab 28 May 1973 to the termination of the Stanford solar radio mapping program 11 August 1973. Synoptic charts of coronal holes were superimposed on the radio charts to determine if the 9.1 cm synoptic charts could be used to identify coronal holes. Their findings lead them to conclude that the 9.1 cm synoptic charts can be of substantial value in identifying large coronal holes, especially during periods of low solar activity. Such synoptic charts, especially during the 1962-65 period of low solar activity, could strengthen the confidence on coronal hole boundaries in the 1960-1973 pre-Skylab period.