Every year we're reminded winter weather is cold and dry. Unfortunately, this reminder comes in the form of complaints, anxiety and unhappiness due to guitar damage - an avoidable situation, often due to a lack of understanding about the issue.
We're going to join the effort made by many others in trying to raise consciousness regarding proper guitar care for those who live in dry and cold winter climates. If you don't know if this applies to you, it does if chapstick is a part of your winter routine or if static electricity is something you experience for example. If your humidity drops below 50% at any time of the year, it applies to you.
Briefly, low humidity can damage your guitar. Since seasonal weather patterns are predictable, it's possible to be prepared for it and do some simple things to protect your instrument.
There are many other authoritative sources who have written everything you need to know on the subject. Here are 2 comprehensive web links which contain the technical, science and tips on what to do about it.
Santa Cruz Guitar Company Fret Not Guitar Repair
There are many other places you can find information such as Frets.com and the Taylor Guitar Company, both excellent sources.
Be informed. Don't let your guitar dry out. Protect your investment.