An imaginary solution 

my $rec = $self->decode($data,
  T => 'at',
  t => 'outside_temp',
  t => 'outside_temp_high',
  t => 'outside_temp_low',
  I => 'rain_clicks',
  I => 'rain_rate_high',
  P => 'barometer',
  I => 'solar_radiation',
  I => 'wind_samples',
  t => 'inside_temp',
  B => 'inside_humidity',
);