Cold Weather Running
I noticed that my feet feel tougher when running in cold weather than when running in hot weather. Something about the temperature softening the skin when its warmer.
I've been running off and on this winter. Its been very moderate here - it still gets up to the mid 40's many days. That is very tolerable for barefoot running.
My runs tend to be from 4 to 7 miles each, about 2 or 3 times per week.