This document describes the CF conventions for climate and forecast metadata designed to promotethe processing and sharing of files created with the netCDF Application Programmer Interface[NetCDF]. The conventions define metadata that provide a definitive description of what the data ineach variable represents, and of the spatial and temporal properties of the data. This enables usersof data from different sources to decide which quantities are comparable, and facilitates buildingapplications with powerful extraction, regridding, and display capabilities.The CF conventions generalize and extend the COARDS conventions [COARDS]. The extensionsinclude metadata that provides a precise definition of each variable via specification of a standardname, describes the vertical locations corresponding to dimensionless vertical coordinate values,and provides the spatial coordinates of non-rectilinear gridded data. Since climate and forecastdata are often not simply representative of points in space/time, other extensions provide for thedescription of coordinate intervals, multidimensional cells and climatological time coordinates, andindicate how a data value is representative of an interval or cell. This standard also relaxes theCOARDS constraints on dimension order and specifies methods for reducing the size of datasets.