Using Stylecraft Special DK, I am using the high temperature of the day for the circle and neutral Parchment for background color.
Squares are sewn together with a simple whip stitch using the leftover long tail from the square.
And please do not ask me how much Parchment I have used, I’ve lost count a long time ago.
16x23 squares (including 2 extra ones to make it a rectangle)

Temperature from this website:
https://www.timeanddate.com/weather/canada/calgary/historic

Temps Scale in Celcius:
-25 -.. Lobelia
-20 - -24 Violet
-19 - -15 Bluebell
-11 - -14 Wisteria
-7 - -10 Empire
-4 - -6 Turquoise
0 - -3 Sherbert

0 - 2 Cypress
3 - 5 Meadow
7 - 10 Pistachio
11- 14 Saffron
15 - 18 Sunshine
19 - 22 Spice
23 - 25 Tomato
26 - 28 Lipstick
26- .. Claret
http://spincushions.com/squaring-the-circle-crochet-patte...