Oh: Another extremely important factor to consider is that as the weather gets colder, your fuel economy will drop, all else being equal.
EG, see:
9 reasons why your winter fuel economy bites! - MetroMPG.com
The fact that you were able to achieve the
exact same fuel economy in your first reported tank in summer conditions, above, as well as your most recent tank in early winter mid-November means your driving style
has effectively improved your fuel economy.