>>1097583traditionally prepared leather doesn't get wet. it repeals water to the point where you can wade through a stream with it. It is quite heavy and stiff though. In germany we have a saying that proper leather pants are those that keep standing after you take them of. Also, it makes you sweat buckets, which is why traditional leather pants are loose and short.
Now I haven't worn traditional leather clothes since I was a child (they're fucking expensive, so the only ones I ever had were inherited ones that had been in use for almost hundred years already), but from what I remember, they were rather comfortable while loose and extremely uncomfortable (sweating) once I got big enough that they sat tightly. Also, they were always stiff when I put them on, but once they had warmed to body temperature I could move freely.
As for non-traditional leather (motorcycle clothes and similiar things), they are rather comfortable outdoors, especially in warm weather as the leather keeps wind and rain out without warming you to the point of sweating. They also need to be broken in and warmed up before you can move freely. in late autumn and winter, my leather jackets (a motorcycle jacket made of bufallo hide and a flight jacket o sheep's pelt) are pretty much the only jackets I use. They are far more comfortable than any "functional" jacket I ever owned and even slightly better than my M65 since they aren't as heavy.