Just for fun, I want to chart my monthly household power consumption year-over-year.  However, I wish to include some reference to monthly temperature so I can determine if my home or behavior is improving, worsening, or holding steady in regards to kWh usage.

The data I am working with:  

    +----------+--------+-----------+----------------+----------+-----------+------------+
    |  Month   | # Days | kWh Usage | Daily kWh Avg. | Avg. Low | Avg. High | Avg. Temp. |
    +----------+--------+-----------+----------------+----------+-----------+------------+
    | Mar 2015 |     32 |      1048 |             33 |       40 |        60 |         50 |
    | Feb 2015 |     29 |      1156 |             40 |       32 |        54 |         43 |
    | Jan 2015 |     33 |      1143 |             35 |       38 |        57 |         47 |
    | Dec 2014 |     30 |       887 |             30 |       39 |        61 |         50 |
    | Nov 2014 |     29 |       645 |             22 |       45 |        67 |         56 |
    | Oct 2014 |     29 |       598 |             21 |       60 |        78 |         69 |
    | Sep 2014 |     32 |       893 |             28 |       70 |        85 |         77 |
    | Aug 2014 |     30 |       965 |             32 |       72 |        87 |         79 |
    | Jul 2014 |     29 |       784 |             27 |       72 |        87 |         79 |
    | Jun 2014 |     32 |      1018 |             32 |       69 |        87 |         78 |
    | May 2014 |     30 |       702 |             23 |       63 |        82 |         72 |
    | Apr 2014 |     33 |       722 |             22 |       50 |        71 |         60 |
    | Mar 2014 |     29 |       830 |             29 |       41 |        62 |         52 |
    | Feb 2014 |     28 |      1197 |             43 |       32 |        52 |         42 |
    | Jan 2014 |     33 |      1100 |             33 |       38 |        59 |         49 |
    | Dec 2013 |     30 |       856 |             29 |       40 |        63 |         51 |
    | Nov 2013 |     33 |       686 |             21 |       48 |        70 |         59 |
    | Oct 2013 |     30 |       527 |             18 |       61 |        77 |         69 |
    | Sep 2013 |     30 |       817 |             27 |       69 |        86 |         77 |
    | Aug 2013 |     28 |       991 |             35 |       72 |        86 |         79 |
    | Jul 2013 |     31 |       993 |             32 |       73 |        86 |         79 |
    | Jun 2013 |     30 |       847 |             28 |       66 |        83 |         74 |
    | May 2013 |     29 |       605 |             21 |       59 |        76 |         67 |
    | Apr 2013 |     34 |       791 |             23 |       47 |        66 |         57 |
    +----------+--------+-----------+----------------+----------+-----------+------------+



I started with a column chart easily comparing month-to-month values:

![Month-to-Month Usage Column Chart][1]

I envisioned a nice background area or line graph mapped to a secondary (right) vertical axis showing the high/low ranges but realized that would be problematic with the multi-year groupings.

It would be easy with one single year:

![2014 kWh Usage with Temperatures][2]

**I am curious to know if anyone can recommend a way of combining all the yearly data into a single chart with temperature comparisons?**

Is there some ratio I could use that could effectively relate the kWh usage to average temperature... or some other display technique I am overlooking... or am I stuck with one chart per year?


  [1]: https://i.sstatic.net/m9awd.png
  [2]: https://i.sstatic.net/r1yF6.png