Climate data exchange
WMO policy and practice for the exchange of meteorological and related data and products including guidelines on relationships in commercial meteorological activities follow the spirit of Resolution 40 which states that:
“Members shall provide on a free and unrestricted basis essential data and products which are necessary for the provision of services in support of the protection of life and property and the well-being of all nations, particularly those basic data and products, as, at a minimum, described in Annex 1 to this resolution, required to describe and forecast accurately weather and climate, and support WMO Programmes”
CLIMAT messages which contribute to the data exchange are a comprehensive monthly climatological data set assembled at land-based meteorological and climatological stations. A CLIMAT message contains parameters such as, monthly mean temperature, mean daily temperature, maximum and minimum temperatures of the month, monthly mean pressure, and monthly mean vapour pressure, total precipitation for the month and total sunshine for the month.
The CLIMAT TEMP which contains monthly upper-air data was discontinued by the Commission for Climatology (CCl) during its fifteenth session held in Antalya, Turkey in February 2010 (Reference CCl-XV report, WMO-No 1054, Resolution 3 (CCl-XV)).
A one-year trial phase for the monthly reporting of daily climate observations was accepted by delegates to the seventeenth session of the Commission for Climatology in April 2018 (see Recommendation 5 (CCl-17)).