Depends on layering and the wind. They are bibs so they are going to hold heat in better while sitting than a pair of pants. These have a cool heavy hexagonal grid fleece interior with a nice smooth face exterior. They are not windstopper treated. If you had proper layering, and weren’t cold natured, you could probably get into the 30’s with them. I’ve read reviews on Sitka site where some guys run them down in those temps, or even lower to the 20’s. If the wind is blowing hard, you may get cold at those temps. With the long leg zips up the the hip, you can run these up to 75 and 80 and dump heat quickly. Very versatile piece just by changing the layering underneath.