Ok, well - I changed my mind on my design. Luckily it's only January 10th and not Sept 10th. 
I decided my HSTs didn't really convey the story of the temperature change very well and didn't really show enough of my fabric. My new plan is to use 1.5" squares. I will do a 31x12 layout for the high temps and a separate 31x12 layout for the low temps. At the end of the year I think I will join these two halves with a strip of sashing to make a single quilt. In that wide sashing I may applique or paper piece an upwards pointing arrow and then the words "2017 Temperatures" and then a downwards pointing arrow. Or I might just add flying geese . Or I might do something else. I have almost a year to figure it out.
So something more or less like this which will give me a reasonably sized wall quilt.
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