The International Meteorological Organization (IMO) was founded in 1873, and worked to perfect and standardize international meteorological practices. In 1950 the World Meteorological Organization (WMO) was organized and replaced the IMO. In 1951 it became a specialized agency of the United Nations for weather and climate, operational hydrology and related sciences.
      In 1973 the WMO celebrated the 100th anniversary of the IMO-WMO with 187 member states. About 75 countries commemorated the centenary with a postal issue or with a special cachet. Among them Ghana issued a souvenir sheet with two stamps. A web page of postal items observing the anniversary is at:

https://rammb.cira.colostate.edu/dev/hillger/IMO-WMO.htm

     The sheet shows cloud formations over a map of Ghana and adjoining countries. Ghana is outlined in purple on the souvenir sheet, with seven towns specifically identified. The adjoining country of Togo is outline to the west of Ghana, as is the eastern part of Côte d’Ivoire on the west. Also a small part of the boundary between Benin and Burkina Faso is indicated northeast of Ghana.
     The low value stamp features a Tiros meteorological satellite of the Global Observing System. The high value has a computer weather map with isolines representing lines of common temperatures or barometric pressure. Both stamps feature the logo of the WMO:

     The stamp issued by Upper Volta (Burkina Faso) in 1963 for World Meteorological Day features a meteorological map of part of Burkina Faso and the logo of the World Meteorological Organization (Organisation Météorologique mondiale).