On 23 March 1950, the World Meteorological Organization (WMO) was formed for meteorology (weather and climate), operational hydrology and related geophysical sciences. It has 188 members.
World Meteorological Day is celebrated worldwide by the meteorological community every year on March 23 to commemorate the organization of WMO. Each year a different theme is chosen for the occasion. WMO was designated a specialized agency of the United Nations System in 1951.