Annex 3 - Meteorological Service for International Air Navigation


Developed by ICAO, the International Standards and Recommended Practices (SARPS) contained in the nineteen Technical Annexes to the Convention on International Civil Aviation (also called Chicago Convention) are applied universally and produce a high degree of technical uniformity which has enabled international civil aviation to develop in a safe, orderly and efficient manner.


From the early days of aviation, it was realized that meteorological information was vital for the planning and a constant factor for the safe conduct of flights; pilots need to be informed about meteorological conditions along the routes to be flown and at their destination aerodromes. The high operating cost of modern aircraft means that optimum use must be made of available meteorological information and that forecasting accuracy must continue to be improved. The increasing use of flight management computers and the establishment on-board aircraft of reliable data links between aircraft and ground make it possible to monitor flight progress and update flight plans on the basis of new weather conditions. 


As the Organization preceding ICAO, the International Commission for Air Navigation (ICAN) held twenty-nine sessions between July 1922 and October 1946, with an interruption during WWII. ICAN had created its own Meteorological Commission and drafted Annex G, named Collection and dissemination of meteorological information, to the Convention for the Regulation of Aerial Navigation.



The Sphinx Observatory

in the 1950s

The Convention on International Civil Aviation, which came into force on 4 April 1947, had made provision for Annex I on Meteorological protection of international aeronautics. As standards were developed by ICAO, either the subjects of annexes were split or new annexes were conceived, and most of the titles were revised. Thus, a new Annex 3 titled Meteorological Codes was first adopted by the Council on 16 April 1948.


With the introduction of Standards and Recommended Practices governing the obligations of Contracting States relating to the establishment of meteorological organization in each State, a change of title of Annex 3 – Meteorology was adopted by the ICAO Council on 1 April 1955.


With a complete revision of Annex 3, incorporating PANS-MET specifications (Procedures for Air Navigation Services, Meteorology), taking into account recently approved operational requirements and up-to-date methods of meeting them and with the introduction of new Standards and Recommended Practices relating to service for operators and flight crew members, meteorological information for air traffic services and for search and rescue services, together with requirements for communications and their use, the title of Annex 3 was, accordingly, amended to read Meteorological Service for International Air Navigation and adopted by the Council on 26 November 1975.


The purpose of this Annex is to make provision of meteorological information to operators, flight crew members, air traffic services units, search and rescue units, airport management and other concerned with aviation.


Working arrangements between ICAO and WMO were agreed and approved by both organizations during 1953 for entry into force on 1 January 1954. The arrangements were designed to secure close cooperation and to establish machinery regarding the allocation to one organization or the other of primary responsibility for certain sectors within the field of common interest. In accordance with that document, ICAO is responsible for specifying the needs of the users/customers of aeronautical meteorological services, whereas WMO is responsible for providing the aviation community with operational meteorological information. WMO and ICAO maintain close and constant cooperation in keeping under review the requirements of meteorological services for aviation and in the adoption of procedures for the provision of these services, as well as keeping them up to date.


United Nations New York – 9 February 1955 – First Day Cover

Tenth anniversary of the International Civil Aviation Organization

Picture of a meteorological station in Switzerland taken in the early 1950s, with a Convair CV-240 in the background. Built in 1937, the Sphinx Observatory, 3,571 metres up in the Jungfraujoch, is maintained by the Swiss Aeronautical Meteorological Service and symbolizes the vigilance of the world’s aviation meteorology networks over international air transport. Observations were made at that time between 6 in the morning and 7 at night.



This pamphlet, describing ICAO’s mission and activities (with texts in English, French and Dutch), was printed in 1955; it shows the Sphinx Observatory, in Switzerland.

The same picture was printed on the front-page of ICAO Bulletin in August 1954.

Service cover sent from the Civil Aviation and Meteorology Authority of Yemen Arab Republic (now Yemen)

to Yves Lambert, Secretary General of ICAO from 1 August 1976 to 31 July 1988.


United Nations Geneva - 26 June 1990 –

First Day Cover - 45th Anniversary of the United Nations

The close relationship among the UN Organizations is depicted on this issue. Numerous Organizations are represented by an identifier, in particular: ICAO by an aircraft and WMO by the sky and clouds.