I'm in north Florida, so obviously it dosen't get very cold here (I used to live in Denver before barefooting, and I can't imagine getting many barefoot runs in during the winter there without wearing Five Fingers or some kind of covering). Maybe everyone goes with minimalist footwear on cold/snowy runs?

So, my "coldest" runs have been a couple of times in the mid-forties. I don't think I could run barefoot in less than 40 degree weather. A couple of times my toes almost felt like your fingers do when they get too cold, but not quite. I think in the 30's, my feet would get numb.

I've thought about running BF on the treadmill when it's too cold, but I have gotten a blister doing that (from the friction of the belt, I guess).  And, most gyms want you to wear shoes.

WWBTD?

MTA:  I googled Barefoot Ted but forgot he lives in sunny Calif.

I live in central SC and manage to run through the winter with bare feet.  I do pick and choose more carefully when to run, though.

I find that I can run down to at least 30F in dry conditions and to about 40F in wet conditions.  My feet often go numb during the first few minutes of a run and take about ten to twenty more minutes to warm back up to normal.  I just have to pay more attention to form during the numb period.

I have yet to run in much snow, as we don't get much here normally.  I have walked around for a couple of minutes barefoot when we have had snow and have run through the thawing snow when there wasn't much left.

I ran a long run today that started in mid-20's temps.  I wore socks until I started and was well bundled up from ankle to head, and my feet did much better than I expected.  It was my longest barefoot run to date.

I've tried to run barefoot in the snow. I simply can't do it. I think the 40's, especially if it's wet, is even worse actually.

I just can't do what Michael Sandler does here for more than .25 miles.

Honestly, it's a bit too risky for me too. I know that if I'm in minimalist shoes and I get hurt, tired, or whatever, I can walk without worrying about my feet needing to be amputated when I arrive at my destination.

I realize you can put a lot of preparation into this to make sure it probably won't happen, but that's a lot more preparation than I want to go run for an hour every day.

So my experience is, gradually build up some barefoot on the treadmill (don't overdo it or you will get blisters, even if it's just walking), and find some kind of shoe/mocassin/sock that you are comfortable that if you had to walk for awhile in, you wouldn't worry about gangreen.

I wrote further about my experimentation on my blog a few years ago.

These days, when it's really cold up in MI, I rely on my RunAmoc with socks. Even running in VFF I've gotten frostbite, especially when you get them wet from road slop. It's a brutal healing process once you get frostbite on your toes.

MTA: Most of my runs are 1 hr+, so of course YMMV.