I take it in tens.

-20° to -10° is full parka weather. Your breath freezes on your clothes and moisture in the air dries up.

-10° to 0° is winter coat and scarf weather. Damp cold. Snow and ice but you don’t feel like your eyeballs are freezing.

0° to 10° Jacket weather. Early spring temps. Pretty mild in either direction.

10° - 20° Hoodie and t-shirt to taste. Basically the comfortable human range for most.

20°- 30° T-shirt time. Anything above 25 is solidly in swimming weather territory.

30°- 40° Time to seek some shade. Heatstroke and heat exhaustion are variable in this range the low end is a health risk for seniors the high end is a risk for even the hardcore heat lovers in their prime.