Outermost layer:
In dry conditions or only light rain/sleet/for a limited time: A cotton/synthetic blend called G1000 by the Swedish firm Fjällräven. It seems to be composed of the same mix as the venerable "511" trousers, but I don't know how the quality compares. Anyway, my Fjällräven pants is by far my favourite pair of outdoors anything trousers for any season with temperatures below 15C / 60F.

In dry winter conditions (dry snow, below freezing), pure cotton has lots of advantages if spun to be wind proof and of the right quality. The "G1000" seems to be slightly better, but modern membrane (goretex or whatever) clothes will still keep you dry longer in wet conditions.


In wet conditions, I typically augment that with a goretex-equivalent pair of trousers that are wide enough to just slide over my boots and all. I also use this as an extra wind blocking/insulation layer if it is really bitterly cold and blowing hard - it gives highly improved wind resistance and a little extra insulation without slowing me down and hinder any movements. My particular pair is of the material "dermizax" made by the Norwegian firm Bergans. Good stuff, but there's tons and tons of similar stuff out there.


Underneath my outer layers, I put one or more layers of merino wool "long johns" (long underpants), depending on temperature and level of activity. Great stuff. I LOVE wool.


All this is for moving about. If I need to stay still I will add a snowmobile suit. Down would be great - maybe next Christmas.