This chapter explores the history of a global governance institution, the World Meteorological Organization (WMO), from its nineteenth‐century origins through the beginnings of a planetary meteorological observing network, the WMO’s World Weather Watch (WWW), in the 1960s. This history illustrates a profoundly important transition from voluntarist internationalism, based on shared interests, to quasi‐obligatory globalism, based on a more permanent shared infrastructure.