These pants are a combination of lycra and wetsuit material. They are good for the temperature 35-60 Farenheit (2-16 Celcius). Below 35 Farenheit you need to double up with a pair of long underwear to be comfortable. They are pretty good for cool and windy days, but with the wetsuit material they suck up the water when it rains which I don't like. That said, they are warm still warm when they are wet. Because of the wetsuit material, they also take quite a while to dry, which means they have the potential to get stinky. I wish they had more reflective material on them as well. They have a small area on the thigh and pinstripping on the ankle zipper which is not enough for dark fall nights. I rate these pants highly since there isn't anything better on the market right now.