Temperature greatly affects the sound, construction and appearance of a guitar. Care must be taken to avoid subjecting your guitar to harsh fluctuations. If you must play outside in the cold or extreme heat, consider using a less expensive guitar to avoid damage to your high-end instruments. Keep your instrument in its case and minimize the time spent performing in temperatures that will warp and distort your guitar.
The tension of the strings will change with temperature. The strings most affected are the thickest strings while the strings least affected are the top higher strings that are slimmer. The overall tension can be increased or decreased depending on the environmental conditions. This will directly affect the tuning of the instrument. Performers need to be aware of how temperature will affect the temperature of the guitar. This makes it possible for the performer to re-tune the guitar as necessary in extreme temperatures.
No noticeable difference in tuning has been detected with cold weather. However, cold weather is known to cause elements to detract. Most instruments when exposed to cold weather will go slightly sharp since the materials tend to contract and create additional tension. The biggest hazard for cold weather storage is that the guitar can warp. The inlays of the guitar can be damaged with prolonged exposure to cold weather, and the bindings and neck of the guitar may also suffer.
Hot weather can cause the strings to loosen, thereby lowering the pitch of the guitar. This is problematic in a performance since not all of the strings are affected the same. It may be necessary to re-tune your guitar every 20 to 30 minutes to maintain the pitch. Heat can also fade the finish of your guitar and warp the body. For this reason, never leave your guitar in a hot car, even for a short period of time.
Humidity can also affect the construction of a guitar. The top of the instrument can begin to expand. You will notice this first as ripples in the finish of the guitar. This will severely affect the sound oas well. The bridge and strings of the guitar may push upwards creating additional tension in the neck of the guitar, destroying the finish. The strings may also be damaged with prolonged exposure to humidity. Strings exposed to high levels of moisture may absorb the water in the air, which will weaken them and make them more prone to breaking.