In Wales Wet = Normal ... you get used to it...
plan it like it's always wet. either keep covered what can get wet or learn to adapt to the damp.
as in fire lighting lots and lots of kindelling, two ways to do this, small branches with lots of twigs,or splitting for a long long time. pine (and I'm informed birch) twigs the best.
seconded's
when bivvying as others have said, the rucksak goes into the strap side of the rucksack, the straps face the floor and either the poncho or a bit of plastic goes over the top and is weighted down by the bag.
Always take more socks than teeshirt, ( they ain't that heavy)
dry kit -in the summer accept you'll get wet, which makes stream crossing a doddle, but that doen't factor in the winter. Dry kit a pair of pumps doesn't weigh much but is very good to have, give your boots and your ankles a rest. my pair weigh 300g
keep everything you can dry, special importance given to the sleeping bag. always take the opportunity to drystuff, even though crispy dried socks aren't that appetising, it helps keep the damp out. damp accumulates so to dry things sun or fire ( or canvas shelter) should be taken.
condensation and humidity will not disperse in the damp, keep all humitity source away, hot drinks cooking, breath, make sure humidity is kept to a minimal
.