The technical commissions usually meet once every four years – except for the Commission for Basic Systems, which holds an extraordinary session in between. The President and Vice-President of each commission are elected at these meetings.
The eight WMO technical commissions are composed of experts in the field of the specific commission. These are designated by Members for their scientific expertise not to act as representatives on their state.
- Commission for Aeronautical Meteorology - CAeM
- Commission for Agricultural Meteorology - CAgM
- Commission for Atmospheric Sciences - CAS
- Commission for Basic Systems - CBS
- Commission for Climatology - CCl
- Commission for Hydrology - CHy
- Commission for Instruments and Methods of Observation - CIMO
- Joint WMO-IOC Commission for Oceanography and Marine Meteorology - JCOMM