The World Meteorological Organization (WMO) is a specialized agency of the United Nations. It is the UN system’s authoritative voice on the state and behaviour of the Earth’s atmosphere, its interaction with the oceans, the climate it produces and the resulting distribution of water resources.
WMO has a membership of 188 Member States and Territories (since 24 January 2007). It originated from the International Meteorological Organization (IMO), which was founded in 1873. Established in 1950, WMO became the specialized agency of the United Nations in 1951 for meteorology (weather and climate), operational hydrology and related geophysical sciences.
As weather, climate and the water cycle know no national boundaries, international cooperation at a global scale is essential for the development of meteorology and operational hydrology as well as to reap the benefits from their application. WMO provides the framework for such international cooperation.
WMO promotes cooperation in the establishment of networks for making meteorological, climatological, hydrological and geophysical observations, as well as the exchange, processing and standardization of related data, and assists technology transfer, training and research. It also fosters collaboration between the National Meteorological and Hydrological Services of its Members and furthers the application of meteorology to public weather services, agriculture, aviation, shipping, the environment, water issues and the mitigation of the impacts of natural disasters.
In keeping with its mandate to promote the standardization of meteorological observations, the WMO maintains numerous code forms for the representation and exchange of meteorological, oceanographical, and hydrological data. The traditional code forms, such as SYNO and TEMP, are character-based and their coding is position-based. Newer WMO code forms are designed for portability, extensibility and universality. These are BUFR, CREX, and, for gridded geo-positioned data, GRIB.
The World Meteorological Congress, the supreme body of the Organization, brings together the delegates of Members once every four years to determine general policies for the fulfilment of the purposes of the Organization, to approve long-term plans, to authorize maximum expenditure for the following financial period, to adopt Technical Regulations relating to international meteorological and operational hydrological practice, to elect the President and Vice-Presidents of the Organization and members of the Executive Council and to appoint the Secretary-General.
The Executive Council, the executive body of the Organization, is responsible to Congress for the coordination of the programmes of the Organization and the utilization of its budgetary resources in accordance with the decision of Congress. Composed of 37 directors of National Meteorological or Hydrometeorological Services, it meets at least once a year to implement the programmes approved by Congress and review the activities of the Organization.
The six regional associations are responsible for the coordination of meteorological, hydrological and related activities within their respective Regions: Region I (Africa), Regional II (Asia), Region III (South America), Region IV (North America, Central America and the Caribbean), Region V (South-West Pacific) and Region VI (Europe). They meet in their respective Regions once every four years, when they elect a president and a vice-president. The president of each regional association is an ex officio member of the Executive Council.
The eight technical commissions, composed of experts designated by Members, study matters within their specific areas of competence (technical commissions have been established for basic systems, instruments and methods of observation, atmospheric sciences, aeronautical meteorology, agricultural meteorology, oceanography and marine meteorology (jointly with IOC of UNESCO), hydrology and climatology).
The Secretariat, headed by the Secretary-General and headquartered in Geneva, serves as the administrative, documentation and information centre of the Organization. It prepares, edits, produces and distributes the publications of the Organization, carries out the duties specified in the Convention and other Basic Documents and provides support to the work of the constituent bodies ovf WMO described above.