Humidify!

It's that time of year again in the Northeast; time to worry about humidity levels (unless you own a Stratocaster or other solid body guitar, in which case skip this post...)

But for acoustic owners, you should be concerned about humidity. Standard disclaimers apply, and I'm not going to go into the whys and wherefores here, but I did come across this interesting specific information about what humidity levels you need to aim for in this post on the UMGF:

"Bob Taylor wrote in “Wood & Steel” a while back [...] that if a guitar was kept in a humidity range that was within 20% of its build conditions, its geometry (the relationship of its various parts to each other) would be fine.

If a guitar is assembled with seasoned wood in a 72 degree F room that is kept at a relative humidity of 45% (typical of the conditions most N.American guitars, including Martin, are assembled in) then a 20% plus/minus range based off of a 45% center would be 36% to 54%."