Hi Brian,
Weather in all mountains is subject to rapid change. More so when the incoming weather comes off an ocean such as your SW coast or various parts of Oz. (we are girt by sea as the song says). Here of course we expect sunburn more than frost bite but exposure to both in the one activation while unlikely isn’t impossible. A number of activations in VK in the last 3 months have been (sensibly) abandoned due to a change in the actual weather vs the forecast.
To fatigue, deteriorating weather and the rush for the pub there is also the more subtle relaxation in concentration due to having had a successful activation. I personally find it harder to descend a slope than to climb it, especially if the surface is loose.
73
Ron