World Meteorological Organization

The World Meteorological Organization (WMO) is the specialized agency of the United Nations responsible for weather, climate and water. Headquartered in Geneva, it has 194 Members and sets the standards that let national weather services share observations and forecasts across borders.

History of the World Meteorological Organization

WMO’s roots go back to 1873 and the International Meteorological Organization (IMO), a non-governmental body. The Vienna International Meteorological Congress of that year set up a Permanent Meteorological Committee to draft rules for an international organization that would help countries exchange weather information. Professor Buys Ballot presided over the committee, which finished its work in Utrecht in 1878, and the IMO was founded at a congress in Rome in 1879.

By the mid-1930s the IMO’s status as a non-governmental body no longer matched the importance meteorology had gained amid economic and technological change. A draft of a new convention, known as the Berlin Draft, was prepared by 1939, but the Second World War delayed action, and the Secretariat moved to neutral Switzerland in 1939. In February 1946 the IMO’s Conference of Directors asked its committee to draft a new constitution that would make it an intergovernmental body.

The WMO came into being on 23 March 1950, when 30 states had deposited their instruments of accession to the WMO Convention at the United Nations. A year later, in 1951, WMO became a specialized agency of the United Nations, and the IMO’s last president, Sir Nelson King Johnson of the United Kingdom, handed over to the new Secretariat.

Structure and membership of WMO

WMO has 194 Members, made up of 188 Member States and 6 Territories that maintain their own meteorological services. Its main goal is to facilitate international cooperation in meteorology and in the exchange of information and technology for weather, climate and hydrology, the study of water.

The organization consists of the World Meteorological Congress, the Executive Council, six Regional Associations and two Technical Commissions. The Congress is the highest decision-making body, and the Executive Council implements its decisions. The two Technical Commissions, the Infrastructure Commission and the Services Commission, review advances in science and technology and recommend international standards.

A Secretariat, which includes four regional offices, supports the work. The Officers of WMO are a President and three Vice-Presidents, who chair and vice-chair the Congress and the Executive Council. Together with the Secretary-General they form the Bureau, an informal consultative body. A Joint WMO-IOC Collaborative Board, an interagency body with the Intergovernmental Oceanographic Commission of UNESCO, coordinates ocean matters of common interest.

What WMO does

WMO describes itself as the United Nations system’s authoritative voice on the state and behavior of the Earth’s atmosphere, its interaction with land and oceans, the weather and climate it produces, and the resulting distribution of water resources. Because weather, climate and the water cycle cross national boundaries, it says international cooperation is essential.

A central task is regulating and facilitating the free and unrestricted exchange of data, products and services in real time or near real time. The United Nations describes the same role as the free international exchange of meteorological data and its use in aviation, shipping, security and agriculture. WMO standards and policies also feed into policy making at national and regional levels.

The World Weather Watch is the best-known framework. After two United Nations General Assembly resolutions, the latest in December 1962, the Fourth World Meteorological Congress in April 1963 approved it as an extension of long-established plans for the facilities and services that meteorological services require. It was organized in three tiers of centers: World Meteorological Centres, regional or specialized centers and national centers. It has grown as an aggregation and coordination of facilities that the Members’ own weather services control.

WMO also co-leads the Early Warnings for All initiative with the United Nations Office for Disaster Risk Reduction, supported by the International Telecommunication Union and the International Federation of Red Cross and Red Crescent Societies. The UN Secretary-General called for it on World Meteorological Day in 2022, with the aim that everyone on Earth be protected by life-saving warning systems by the end of 2027. It rests on four elements: disaster risk knowledge, detection and forecasting, warning communication, and preparedness and response.

Funding and governance of WMO

WMO has two main sources of funding. Assessed contributions are annual amounts due from each Member, set as a percentage of the approved Regular Budget. The percentages follow the United Nations scale of assessment, adjusted for differences in membership, with a minimum rate of 0.02 percent. The World Meteorological Congress approves the scale. Each Member pays its assessment for a two-year period in two halves, due on 1 January of each of the two years.

The Regular Budget is denominated in Swiss francs, the organization’s main operating currency, and the Executive Council approves it for two-year periods. Documents for the 2026 to 2027 and 2024 to 2025 budgets are available on the WMO website.

Voluntary contributions come from governments, international organizations, climate funds, private sector entities and foundations. They are provided for thematic priorities or for specific programs and projects. This entry gives no budget total, because the current figures sit in the budget documents rather than the pages that were read.

Legacy and impact of WMO

WMO turned a non-governmental scientific network into an intergovernmental body with its own convention. Its stated purpose today, to facilitate the exchange of weather information across national borders, follows the aim set for the first international organization in 1873.

The organization’s work now extends beyond forecasts to long-term issues such as climate change and water resources. Its WMO Awards recognize contributions to meteorology, research breakthroughs and the work of young scientists and engineers. Through the Early Warnings for All initiative, it has also put forward a concrete target for disaster warning coverage by 2027.

Editorially reviewed by Specialty Digest Editorial TeamLast reviewed November 4, 2026Researched and drafted with AI assistanceReport an issue