UKC

I'm trying to work out if I need to invest in some warmer layers for a trip to Rjukan in Feb, have climbed in similar temps in the alps but obviously will be standing around for longer with a lower HR in Norway. 

How cold are we talking, more layers than a grim day in Scotland? Full on nuclear winter?

Reckon this is a good excuse to get some new gaitered B3s?

+5 to -25c depending on the winter. A good fit that still allows blood to circulate is equally, if not more critical than the boot itself. 

A few years ago it was between -14 and -5 the whole time I was there. The other thing to remember is that Rjukan gets no sun either. Wasn't bad with standard winter gear and a good belay jacket. I often got down to just baselayer and softshell while climbing. 

I was there a few years ago. The gauge in the town was showing -30. As we descended into the gorge we could feel a significant temperature drop every metre or so that we went down.  It must have been -40 or more in the valley bottom.  The ice was like concrete.

Al

Last couple of years I was out it was 5-8 degrees first trip and -12 to -15 the following year.  Used heavyweight baselayer, fleece and softshell both trips coupled with thick down for belays. I wear old Scarpa leather winter boots and have been warm enough in them. It is dry cold so doesn't permeate like damp does.

I've typically worn similar layers in both Norway and Scotland. Always had warm boots for both though. Previously Omegas, now Batura 2s.

Temps might be colder than in Scotland, but from my brief encounter to the joys of Scottish Winter. Well, it is dry cold. So easier to handle and to stay warm when not soakin’ wet a’la Scotland.

Been a few times, worse it got to was about -17 but I never really felt cold, I think the lack of wind helps when compared to Scotland.