About the Manual on Codes Volume I.2
Manual on Codes (WMO-No. 306), Volume I.2 - Part B and Part C
Annex II to the WMO Technical Regulations
Coded messages are used for the international exchange of meteorological information comprising observational data provided by the WMO Integrated Global Observing System and processed data provided by the WMO Integrated Processing and Prediction System (formerly Global Data-processing and Forecasting System). Coded messages are also used for the international exchange of observed and processed data required in specific applications of meteorology to various human activities and for exchanges of information related to meteorology.
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Download from the WMO library
Manual on Codes (WMO-No. 306), Volume I.2 [2025 edition]
Download machine-readable codes
The latest version of the machine-readable codes.
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View amendments
Status: DRAFT
Proposed implementation date: 17 November 2025
Status: APPROVED
Implementation date: 19 May 2025
View all previous amendments.
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This manual includes
- Part B section b
- FM92-XIV GRIB
- FM94-XIV BUFR
- Part B section c
- WMO-CF Extensions
- Part C section c
- Common Code tables
- Part C section d
- Regulations for reporting traditional observation data in table-driven code forms (TDCF): BUFR or CREX
- Part C section e
- Regulations for reporting GBON parameters
- Part C, Attachment I
- Templates for the transmission in BUFR or CREX of other data types.
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Working Areas
The Expert Team on Data Standards (ET-Data) maintains the codes in GitHub repositories.
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Guidance
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Legacy Editions
Deprecated versions are available here for reference.
~ this page was last updated on 21 August 2025 ~