Two attributes, missing_value and _FillValue, are used to represent missing or undefined data in a netCDF file. These values are treated as NoData in a netCDF raster layer.
In a netCDF feature layer, they are treated differently depending on where they appear. In station data, if missing_value or _FillValue appears in X or Y variables, then no feature is created at that location. However, when they appear in variables, the feature attribute table is populated with null. In uniformly distributed gridded points, if missing_value or _FillValue appears either in a variable or in an X or Y variable, then no feature is created at that location.
In a netCDF table, missing_value or _FillValue appears as null. You must exclude these values when performing operations or creating graphs.