30 degrees?
20 degrees?
What about 10 degrees? Brrrrrr!
Like Cappy I wore short sleeve shirts year round until I retired. It was easier to wash my arms than to clean a shirt sleeve during the day at work. If I was only going to be outside for 10 minutes or so I didn't add any clothes. Maybe if it was below zero I shortened the time a bit. Strange thing, after having heart bypass surgery I can stand the cold even better. I like to joke that they must have cut the wires to my body thermostat when they ran that saw up my chest. Now I have a part time job where I have to be outside for an hour and a half in the early morning and again in the afternoon and I do put on layers. 30 degrees = sweater plus jacket, 20 = add fleece vest, 10 = add winter jacket, 0 add lined flannel shirt. My hands need to be out often to control traffic so I carry hand warmers in my jacket pockets if it's below 30.
Oh, I wear clothes too...
Running - 2 layers
Cycling - third layer windbreaker as outer shell
When I am out snow blowing, I wear a knit hat, scarf or neck gator, t-shirt, sweatshirt, ski jacket, light long johns under warm-up pants, and my thinsulate boots.
Normal, going shopping, etc...jeans, t-shirt, sweatshirt, medium jacket. Nothing big. You get used to the climate you are in more than anything.
30 or above - Carhartt coat, 200g thinsulate boots
20 or above - " " with a light hooded sweatshirt under it, generic gloves
10 or above - see 20 or above but switch to warmer gloves and add some wool socks
below 10 - heavier sweatshirt, stocking cap if going to be out for any length of time, 800g thinsulate boots