Still a lot of strange stuff emerging here.

I'm surprised so many Mudcatters still have playable guitars.

Really, rather than trying to understand the varied, conflicting and sometimes nonsensical contributions in this thread, anyone lacking confidence and/or experience really would be best advised to take any decent guitar to a pro for adjustments.

Truss rods are to counteract the string tension that naturally tries to pull the wood of the neck into a bow. The adjustable kinds are also used to set the amount of neck relief (bow). Different players like differing amounts of relief, so there is not just one right spec, although many manufacturers give guideline starting points from which individual players may vary to their taste.

Before messing with the truss rod it may be a good idea to check out other things that can be affected by the weather. As fretboards change a little with humidity frets sometimes raise a little out of their slots. Might just be worth checking that first.