I ride my recumbant trike almost every day even on the cold days.  I about froze my feet off using other socks I had.  These socks have been excellent even in 30-40 degree weather.  They appear to absorb the moisture and my feet stay dry.  I did go out the other day in sub freezing weather and my feet did get cold after about an hour.  I wouldn't recommend these in temps less than freezing, however, I still use them in pretty frigid weather.  If it's too cold to use them, then it's TOO COLD and I stay home!