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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Manual on Codes (WMO-No. 306), Volume I.2 [2025 edition]
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Recent amendments
Links to proposals for amendments will be available here until a new version of the Manual is republished.
- FT2026-2: FINAL DRAFT
- Expected implementation date: 1 December 2026
- FT2026-1: APPROVED
- FT2025-2: APPROVED
- FT2025-1: APPROVED
View archive of all amendments since 2009.
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.
Guidance
- Guidance materials to table-driven code formats - Note: The guidance is not actively maintained but may still provide useful information.
Legacy Editions
Working Areas
The Expert Team on Data Standards (ET-Data) maintains the codes in GitHub repositories.