Anonymous Monk,
Each element of the array points to an anonymous hash containing exactly two keys. I doubt you would prefer this syntax any better:

@{$envars[0]}{qw(value description)} = ('23' , 'temperature in Celsius
+');
@{$envars[1]}{qw(value description)} = ('56' , 'relative humidity in %
+');
[download]

If you can, you might want to change to a hash of arrays:

@{ $envars{value} } = qw(23 56 1008.1 4 344);
@{ $envars{description} } = (
    'temperature in Celsius',
    'relative humidity in %',
    'pressure in millibars %',
    'dwpoint in degrees Celsius',
    'total column ozone in Dobson Units'
);
[download]

Cheers - L~R