The World Meteorological Organization (WMO) is a specialized agency of the

United Nations The United Nations (UN) is the Earth, global intergovernmental organization established by the signing of the Charter of the United Nations, UN Charter on 26 June 1945 with the stated purpose of maintaining international peace and internationa ...

responsible for promoting international cooperation on

atmospheric science Atmospheric science is the study of the Atmosphere of Earth, Earth's atmosphere and its various inner-working physical processes. Meteorology includes atmospheric chemistry and atmospheric physics with a major focus on weather forecasting. Clima ...

climatology Climatology (from Greek , ''klima'', "slope"; and , '' -logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. Climate concerns the atmospher ...

hydrology Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydro ...

and

geophysics Geophysics () is a subject of natural science concerned with the physical processes and Physical property, properties of Earth and its surrounding space environment, and the use of quantitative methods for their analysis. Geophysicists conduct i ...

. The WMO originated from the International Meteorological Organization (IMO), a nongovernmental organization founded in 1873 as a forum for exchanging weather data and research. Proposals to reform the status and structure of the IMO culminated in the World Meteorological Convention of 1947, which formally established the World Meteorological Organization. The Convention entered into force on 23 March 1950, and the following year the WMO began operations as an

intergovernmental organization Globalization is social change associated with increased connectivity among societies and their elements and the explosive evolution of transportation and telecommunication technologies to facilitate international cultural and economic exchange. ...

within the UN system. The WMO is made up of 193 countries and territories, and facilitates the "free and unrestricted" exchange of data, information, and research between the respective meteorological and hydrological institutions of its members. It also collaborates with nongovernmental partners and other international organizations on matters related to

environmental protection Environmental protection, or environment protection, refers to the taking of measures to protecting the natural environment, prevent pollution and maintain ecological balance. Action may be taken by individuals, advocacy groups and governments. ...

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

, resource management, and socioeconomic development. Headquartered in Geneva, Switzerland, the WMO is governed by the World Meteorological Congress, composed of member states, which meets every four years to set policies and priorities. The Congress is led by an Executive Council led by the President, currently Abdulla Al Mandous of UAE.

Governance

Gerhard Adrian at World Meteorological Organization

The WMO was established by the Convention of the World Meteorological Organization, signed 11 October 1947 and ratified on 23 March 1950. The Convention serves as the constituent treaty of the WMO, setting forth its purposes, governance, and general framework. The WMO hierarchy: *The World Meteorological Congress, the supreme body of the Organization, determines policy. Each member state and territory is represented by a Permanent Representative with WMO when Congress meets every four years. Congress elects the President and vice-presidents of the Organization and members of the Executive Council; and appoints the Secretary-General. *The Executive Council (EC) implements Congress decisions. *The Secretariat is an eight-department organization with a staff of 200 headed by a Secretary-General, who can serve a maximum of two four-year terms. The annually published WMO Statement on the status of the World Climate provides details of global, regional and national temperatures and extreme weather events. It also provides information on long-term climate change indicators including atmospheric concentrations of greenhouse gases, sea level rise, and sea ice extent. The year 2016 was the hottest year on record, with many weather and climate extremes, according to the most recent WMO report. As of August 2023, the WMO has a membership of 193 member states and territories.

List of secretaries-general

* 1952–1955 Gustav Swoboda () * 1956–1979 David Arthur Davies () * 1980–1983 Aksel C. Wiin-Nielsen () * 1984–2003 Godwin Obasi () * 2004–2015 () * 2016–2023 Petteri Taalas () * 2024–present Celeste Saulo ()

WMO Strategic Plan

* Disaster risk reduction * The Global Framework for Climate Services (GFCS) * The WMO Integrated Global Observing System (WIGOS) * Aviation meteorological services * Polar and high mountain regions * Capacity development * Governance

Meteorological codes

In keeping with its mandate to promote the standardization of meteorological observations, the WMO maintains numerous code forms for the representation and exchange of meteorological, oceanographical, and hydrological data. The traditional code forms, such as SYNOP,

CLIMAT CLIMAT is a code for reporting monthly climatological data assembled at land-based meteorological surface observation sites to data centres. CLIMAT-coded messages contain information on several meteorological variables that are important to monitor ...

and TEMP, are character-based and their coding is position-based. Newer WMO code forms are designed for portability, extensibility and universality. These are BUFR, and, for gridded geo-positioned data,

GRIB GRIB (GRIdded Binary or General Regularly-distributed Information in Binary form) is a concise data format commonly used in meteorology to store historical and forecast weather data. It is standardized by the World Meteorological Organization's ...

Recognitions received

In 2007, the

Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations. Its job is to "provide governments at all levels with scientific information that they can use to develop climate policies". The World Met ...

(IPCC), a joint creation of the WMO and the

United Nations Environment Programme The United Nations Environment Programme (UNEP) is responsible for coordinating responses to environmental issues within the United Nations system. It was established by Maurice Strong, its first director, after the Declaration of the United Nati ...

(UNEP), received the

Nobel Peace Prize The Nobel Peace Prize (Swedish language, Swedish and ) is one of the five Nobel Prizes established by the Will and testament, will of Sweden, Swedish industrialist, inventor, and armaments manufacturer Alfred Nobel, along with the prizes in Nobe ...

"for their efforts to build up and disseminate greater knowledge about

anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Anthropogenic may also refer to things that have been generated by humans, as follows: * Human impact on the enviro ...

(man-made)

, and to lay the foundations for the measures that are needed to counteract such change."

World Meteorological Day

The World Meteorological Day is held annually on 23 March.

Use of the International System of Units

WMO states that "the

International System of Units The International System of Units, internationally known by the abbreviation SI (from French ), is the modern form of the metric system and the world's most widely used system of measurement. It is the only system of measurement with official s ...

(SI) should be used as the system of units for the evaluation of meteorological elements included in reports for international exchange." The following units, which include units which are not SI units, are recommended by the WMO for meteorological observations: * Degrees Celsius (°C) for

temperature Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...

, or alternatively

Kelvin The kelvin (symbol: K) is the base unit for temperature in the International System of Units (SI). The Kelvin scale is an absolute temperature scale that starts at the lowest possible temperature (absolute zero), taken to be 0 K. By de ...

(K). *

Metres per second The metre per second is the unit of both speed (a scalar quantity) and velocity (a vector quantity, which has direction and magnitude) in the International System of Units (SI), equal to the speed of a body covering a distance of one metre in ...

(m/s) for

wind speed In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in temperature. Wind speed is now commonly measured with an anemometer. Wind spe ...

. * Degrees clockwise from north (°) for

wind direction Wind direction is generally reported by the direction from which the wind originates. For example, a ''north'' or ''northerly'' wind blows from the north to the south; the exceptions are onshore winds (blowing onto the shore from the water) and ...

, or alternatively on the scale 0–36, where 36 is the wind directly from north and 09 is the directly wind from east. * Hectopascals (hPa) for

atmospheric pressure Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1,013. ...

. * Percent (%) for

relative humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog t ...

. * Millimetres (mm) for

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...

(or the equivalent unit kilograms per square metre (kg/m²)). * Millimetres (mm) for

evaporation Evaporation is a type of vaporization that occurs on the Interface (chemistry), surface of a liquid as it changes into the gas phase. A high concentration of the evaporating substance in the surrounding gas significantly slows down evapora ...

. * Millimetres per hour (mm/h) for precipitation intensity, or alternatively kilograms per square metre per second (kg m⁻² s⁻¹). * Hours (h) for sunshine duration. * Metres (m) for

visibility In meteorology, visibility is the measure of the distance at which an object or light can be clearly discerned. It depends on the Transparency and translucency, transparency of the surrounding air and as such, it is unchanging no matter the amb ...

. * Metres (m) for cloud height. * Standard geopotential metre (m') for geopotential height. * Kilograms per square metre (kg/m²) for snow water equivalent. *

Watt The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), quantify the rate of Work ...

s per square metre (W/m²) for irradiance. *

Joule The joule ( , or ; symbol: J) is the unit of energy in the International System of Units (SI). In terms of SI base units, one joule corresponds to one kilogram- metre squared per second squared One joule is equal to the amount of work d ...

s per square metre (J/m²) for radiant exposure. * Oktas for cloud cover.

Main public outreach materials

* The World Meteorological Organization at a Glance * WMO for Youth * WMO Bulletin (twice annually) * WMO Greenhouse Gas Bulletin (annually) * WMO Statements on the Status of the World Climate (annually) * In September 2020 the WMO

published Publishing is the activities of making information, literature, music, software, and other content, physical or digital, available to the public for sale or free of charge. Traditionally, the term publishing refers to the creation and distribu ...

a high-level brief compilation of the latest

climate science Climatology (from Greek , ''klima'', "slope"; and , '' -logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. Climate concerns the atmospher ...

information from the WMO, GCP, UNESCO-IOC,

IPCC The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations. Its job is to "provide governments at all levels with scientific information that they can use to develop climate policies". The World M ...

UNEP The United Nations Environment Programme (UNEP) is responsible for coordinating responses to environmental issues within the United Nations system. It was established by Maurice Strong, its first director, after the Declaration of the United Nati ...

and the

Met Office The Met Office, until November 2000 officially the Meteorological Office, is the United Kingdom's national weather and climate service. It is an executive agency and trading fund of the Department for Science, Innovation and Technology and ...

. The ''United in Science 2020 Report'' is subdivided into 7 chapters, which each have a list of key messages.

WMO awards and prizes

*International Meteorological Organization Prize *Professor Dr Vilho Väisälä Awards *Norbert Gerbier-Mumm International Award (suspended in 2014) *WMO Research Award for Young Scientists *Professor Mariolopoulus Award

Membership

As of 2023, WMO Members include a total of 187 Member States and 6 Member Territories. Eight United Nations member states are not members of WMO:

Equatorial Guinea Equatorial Guinea, officially the Republic of Equatorial Guinea, is a country on the west coast of Central Africa. It has an area of . Formerly the colony of Spanish Guinea, its post-independence name refers to its location both near the Equ ...

Grenada Grenada is an island country of the West Indies in the eastern Caribbean Sea. The southernmost of the Windward Islands, Grenada is directly south of Saint Vincent and the Grenadines and about north of Trinidad and Tobago, Trinidad and the So ...

Liechtenstein Liechtenstein (, ; ; ), officially the Principality of Liechtenstein ( ), is a Landlocked country#Doubly landlocked, doubly landlocked Swiss Standard German, German-speaking microstate in the Central European Alps, between Austria in the east ...

Marshall Islands The Marshall Islands, officially the Republic of the Marshall Islands, is an island country west of the International Date Line and north of the equator in the Micronesia region of the Northwestern Pacific Ocean. The territory consists of 29 c ...

Palau Palau, officially the Republic of Palau, is an island country in the Micronesia subregion of Oceania in the western Pacific Ocean. The Republic of Palau consists of approximately 340 islands and is the western part of the Caroline Islands ...

Saint Kitts and Nevis Saint Kitts and Nevis, officially the Federation of Saint Christopher (St Kitts) and Nevis, is an island country consisting of the two islands of Saint Kitts and Nevis, both located in the West Indies, in the Leeward Islands chain of the Less ...

Saint Vincent and the Grenadines Saint Vincent and the Grenadines, sometimes known simply as Saint Vincent or SVG, is an island country in the eastern Caribbean. It is located in the southeast Windward Islands of the Lesser Antilles, which lie in the West Indies, at the south ...

and

San Marino San Marino, officially the Republic of San Marino, is a landlocked country in Southern Europe, completely surrounded by Italy. Located on the northeastern slopes of the Apennine Mountains, it is the larger of two European microstates, microsta ...

Cook Islands The Cook Islands is an island country in Polynesia, part of Oceania in the South Pacific Ocean. It consists of 15 islands whose total land area is approximately . The Cook Islands' Exclusive Economic Zone (EEZ) covers of ocean. Avarua is its ...

and

Niue Niue is a self-governing island country in free association with New Zealand. It is situated in the South Pacific Ocean and is part of Polynesia, and predominantly inhabited by Polynesians. One of the world's largest coral islands, Niue is c ...

are WMO Members but non-members of the United Nations.

Vatican City Vatican City, officially the Vatican City State (; ), is a Landlocked country, landlocked sovereign state and city-state; it is enclaved within Rome, the capital city of Italy and Bishop of Rome, seat of the Catholic Church. It became inde ...

and

State of Palestine Palestine, officially the State of Palestine, is a country in West Asia. Recognized by International recognition of Palestine, 147 of the UN's 193 member states, it encompasses the Israeli-occupied West Bank, including East Jerusalem, and th ...

and the states with limited recognition are not members of either organization. The six WMO Member Territories are the

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies. * British national identity, the characteristics of British people and culture ...

Caribbean Territories (joint meteorological organization and membership),

French Polynesia French Polynesia ( ; ; ) is an overseas collectivity of France and its sole #Governance, overseas country. It comprises 121 geographically dispersed islands and atolls stretching over more than in the Pacific Ocean, South Pacific Ocean. The t ...

, Hong Kong,

Macau Macau or Macao is a special administrative regions of China, special administrative region of the People's Republic of China (PRC). With a population of about people and a land area of , it is the most List of countries and dependencies by p ...

Curaçao Curaçao, officially the Country of Curaçao, is a constituent island country within the Kingdom of the Netherlands, located in the southern Caribbean Sea (specifically the Dutch Caribbean region), about north of Venezuela. Curaçao includ ...

and

Sint Maarten Sint Maarten () is a Countries of the Kingdom of the Netherlands, constituent country of the Kingdom of the Netherlands located in the Caribbean region of North America. With a population of 58,477 as of June 2023 on an area of , it encompasses ...

(joint meteorological service and membership) and

New Caledonia New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...

Membership by regional associations

Regional Association I (Africa)

Region I consists of the states of Africa and a few former colonial powers. Region I has 57 member states and no member territories: Non-member *Equatorial Guinea

Regional Association II (Asia)

Region II has 33 member states and 2 member territories. The member states are: The member territories are: *Hong Kong *Macau

Regional Association III (South America)

Region III consists of the states of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

, including France as

French Guiana French Guiana, or Guyane in French, is an Overseas departments and regions of France, overseas department and region of France located on the northern coast of South America in the Guianas and the West Indies. Bordered by Suriname to the west ...

is an overseas region of France. It has a total of 13 member states and no member territories:

Regional Association IV (North America, Central America and the Caribbean)

Region IV consists of the states of

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Central America Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...

, and the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

, including three European states with dependencies within the region. It has a total of 25 member states and 2 member territories. The member states are:

Regional Association V (South-West Pacific)

Region V consists of 23 member states and 2 member territories. The member states are:

Regional Association VI (Europe)

Region VI consists consist of all the states in Europe as well as some

Western Asia West Asia (also called Western Asia or Southwest Asia) is the westernmost region of Asia. As defined by most academics, UN bodies and other institutions, the subregion consists of Anatolia, the Arabian Peninsula, Iran, Mesopotamia, the Armenian ...

. It has 50 member states:

States with membership in more than one region

A total of ten member states have membership in more than one region. Two nations are members to four different regions, while eight are members of two regions. These nations, with their regions, are as follows:

References

External links

* * * * {{Authority control United Nations specialized agencies International climate change organizations Meteorological organizations Hydrology organizations International scientific organizations Standards organisations in Switzerland United Nations Development Group United Nations organizations based in Geneva Scientific organisations based in Switzerland Environmental organizations established in 1950 Scientific organizations established in 1950 1950 establishments in Switzerland Organisations based in Geneva