I then simply divided the AH used by the distance and averaged these values for each month.
The range line (purple) is that figure divided into 16 - my pack is 20AH and 16 is 80% of the pack's AH capacity.
The result. (In Australia the hottest months are January/February - coldest is around June/July).
It's not aligned but here is the temperature graph for where I live. The grey area is the rolling average.