Below is some information from Taylor guitars regarding Humidity and how it can affect you instrument.
Essential products for instrument care and humidifcation are found HERE
Please read the following links from Taylor Guitars:
Symptoms of a Wet Guitar
Symptoms of a Dry Guitar
Using a Guitar Humidifier
Owners should be aware that problems can occur with any style of guitar but are more prevalent with higher priced & solid timber guitars. As this is related to the guitars storage conditions it is not generally covered under normal purchase or repair warranties.