World Meteorological Day takes place every year on 23 March and commemorates the coming into force on 23 March 1950 of the Convention establishing the World Meteorological Organization (WMO).

WMO, the headquarters of which are at Geneva, is an intergovernmental organisation with a membership of 187 Member States and Territories. It became the specialised agency of the United Nations for meteorology, operational hydrology and related geophysical sciences, and originated from the International Meteorological Organization (IMO), which was founded in 1873. The purpose of WMO is to promote international cooperation between meteorological stations around the world, standardise meteorological observations, further develop research and training, and extend the application of meteorological findings to different fields.

World Meteorological Day showcases the essential contribution of National Meteorological and Hydrological Services to the safety and wellbeing of society and is celebrated with activities around the world.  The themes chosen for World Meteorological Day reflect topical weather, climate or water-related issues.

2021 – The ocean, our climate and weather

Covering some 70% of the Earth’s surface, the ocean is a major driver of the world’s weather and climate. It also plays a central role in climate change. The ocean is also a major driver of the global economy, carrying more than 90% of world trade and sustaining the 40% of humanity that lives within 100 km of the coast. Recognizing this, National Meteorological and Hydrological Services and researchers regularly monitor the ocean and how it is changing, modeling how it affects the atmosphere and delivering a wide variety of marine services, including supporting coastal management and Safety of Life at Sea. Today, the growing impacts of climate change are making ocean observations, research and services more critical than ever before.