Beginning in 1853, many of the world's leading maritime countries tried to establish an international system for collecting meteorological observations made by ships at sea.
The first international meteorological congress was held in Vienna in 1873; it led to the founding of the International Meteorological Organization, composed of directors of meteorological services from various countries and territories throughout the world. This body carried out ambitious programs to perfect and standardize international meteorological practices.
As transportation, communications, agriculture, and industry developed in the 20th century, they increasingly relied on meteorology, while meteorology itself relied to an increasing extent on advances in science and technology to perfect its methods of observing and predicting weather phenomena. Hence, the closest possible collaboration was called for between the International Meteorological Organization and other international bodies.
A conference of directors of national meteorological services met in Washington in 1947 under the auspices of the International Meteorological Organization and adopted the World Meteorological Convention, establishing the World Meteorological Organization as a UN specialized agency. On 23 March 1950, after 30 signers had ratified or acceded to the convention, it came into force. The first WMO congress opened in Paris on 19 March 1951.