Hiking clothes for 20-40 degrees

20 – 40 degrees, I have hiked in Patagonia silk weight base layer and a pair of light weight running shorts over them. I was fine. I tend to run warm.. So take it with a grain of salt.

I have also hiked in a pair of marmot scree soft shell pants in those temps.. Which had me very warm on my climbs.. But cozy and comfy while hiking at a leisurely pace, across the peaks, and on breaks.

The question you asked is tough to answer because everyone is different..

Either pant set-up would serve me well in the 30’s.  I suspect prolonged hiking in the 20’s would push me to wear both tights and nylon windpants (but I use very light windpants and tights).  Hope it helps.

I would add a neck gaiter. I find them very warm and, excepting a hat, it is the easiest thing to adjust as you get warmer. I would also have my base layer be long-sleeved because when it gets warm, I’ll still want something over my arms even after I’d set aside the windshirt and fleece.