This reminds me about how I always say I should keep a diary of the temps and what I wore to exercise outside, so I can remember next time how to properly dress for the weather.
Knee boots - with socks and skinny jeans - 45 and below
Knee boots - with tights (no socks) and a dress - 55 and below
Ankle boots - with warm socks or with thin trouser socks - 55 and below
Fashion sneakers - Converses - 55 and above
Fashion sneakers - that have a thicker sole - 32 and above (assuming it's not snowing); I have a pair that get too hot above 65, but are quite toasty even in freezing weather.
Pumps - with tights - if a formal event requires it, any weather though I may wear Uggs to get there.
Pumps/flats - without tights - 55ish and above assuming I'm wearing jeans and not a skirt. My rule of thumb is this: if it's warm enough to wear a spring or fall jacket and not my winter coat, then it is warm enough to go without tights and wear pumps and flats. But this does not apply to skirts/dresses. Going bare-legged with these.... probably doesn't happen until it hits closer to the 70s. This year I will try pairing my spring skirts with boots and no tights... a look I have never done because I think my feet will get sweaty and yucky without tights. But, I'll *try.*
Sandals - at least 75.
I have seen tons of people here in Boston wearing thong flip-flops in 45-55 degree weather! While still wearing winter coats on top. It just seems very WRONG to me. Unless one is running in and out of the nail shop to get a pedicure.
P.s. 10 years ago I would've said a lot differently, but since I hit my 40s I find I run much hotter than I used to!