On what date is World Meteorological Day celebrated each year?

World Meteorological Day is celebrated each year on 23 March. The date commemorates the 1950 entry into force of the convention that created the World Meteorological Organization, or WMO.

The WMO coordinates international cooperation in weather, climate, hydrology, and related Earth sciences. Weather systems cross national borders, so shared observations and common standards are essential for forecasting storms, floods, heatwaves, and other hazards. National meteorological services exchange measurements through global systems supported by the organization.

The first World Meteorological Day was observed in 1961. Each year has a different theme highlighting an issue such as climate information, early warnings, weather services, or water resources. The celebration is therefore both a commemorative date and a public-awareness event.

World Meteorological Day is sometimes confused with World Weather Day or with Earth Day, but these are not the same observances. Earth Day is held on 22 April, while the meteorological event specifically marks the international treaty behind the WMO.