Day trips but I want to have the ability to be comfortable down to 15 deg or so if I had to be out for the night.
I’m assuming you’re going to be moving around with periods of being static. So layers are going to be key that you can put on or take off depending on your activity level.
Baselayer, mid-layer, puffy, and hardshell is usually what I plan on for fall backpacking. However I won’t necessarily be wearing all of that all the time. Start off with a baselayer, add a mid-layer for hiking/being active. I may put a hardshell on top if wet or windy. I found that unless it’s really cold I usually don’t wear a puffy while I’m hiking but I want it when I stop for a while or when I stop in the evenings. Wearing too much while hiking means I sweat, then the sweat makes me cold.
Baselayer: I like merino wool for my baselayers: long johns, long sleeve top, socks, buff, and beanie. 100 weight for early fall, 250 for late season.
Mid-layer: I like to have my mid-layer with a hood. Mid-layer can be a fleece or a light insulated layer but I want it to be breathable. I currently go back and forth between a Kuiu Peloton 1/4 zip hoodie or Outside Vitals Ventus hoodie.
Pants: Some sort of soft shell material with zip vents to dump heat when it warms up or I warm up from activity. I also like it to be DWR treated to repel water but still breathe. Kuiu Attack or Guide pants kind of fit this bill for me, but I’m always looking for something better.
Puffy: Currently I use a down puffy with hood. Since it’s gonna be in my pack I want it to be lightweight (<10 oz) and very compressible, that means down fill. I usually stuff the puffy into a dry bag to keep it dry while hiking and to save space in my pack. Outdoors Vital NovaUL is what I’ve been using.
Hardshell: I’ve been on the hunt for a good hardshell which is waterproof but doesn’t wet out from the inside from sweat. Up until now I’ve been using a hardshell from REI but just got an Outdoors Vital Tushar rainshell to try out.
Neck and head: If you’re like me, I lose a ton of heat from my neck and head, so I usually wear at least a buff around my neck and a wool beanie. Having a hoodie in the various layers also helps to retain heat when I stop moving.
As far as over-night stuff, for me a biggie is going to be an insulated air mattress, something like the Nemo Tensor All-season that has a 5 R-value or even the Tensor Extreme which is designed for winter camping with a R-value upwards of 8. I suppose if you don’t want to carry an air mattress (they weigh 17-24 oz) at least bring a 3-4’ section of closed-cell foam pad that you can sit on to keep your butt off the cold ground. And short of bringing a sleeping bag or top quilt, at least a space blanket or one of those mylar emergency blankets/sleeping bag combos and wear everything you’ve got.
Small stove and pot for heating water. A hot meal and hot drink can really warm you up from the inside.
Hope this helps.
