With the cooler weather right around the corner it got me to thinking about base layers. It is getting close to needing to replace mine. So, I was wondering what are the good light weight options for me to look at? I won't be out in below 0* if that makes a difference on any input.

I was searching out a layering system that would work for me on the Appalachian Trail beginning in March. up to this point I had been doing mostly 100% merino. With the humidity of the South in mind I switched up a little. I am now using the patagonia merino 1 long sleeve 65% merino(4 oz) followed by one of the new (2012) Patagonia Capilene 4 hoody's with the grid fleece inside (9 ounces) It has kept me warm down to 20 in Montana this week and should be more than enough for my Through hikes early days. I also carry a down jacket (8 ounces)

The Rab Meco line is also very nice and I use the 120 weght for my bottoms. They are available at Prolitegear.com.