What Is the Ideal Humidity Level for Guitar?

The Ideal Humidity Level for Guitar featured photo

If you’re a proud owner of a guitar, then you know that your instrument is an investment. You practice with it and enjoy making music with it, but did you know that the humidity level in your home or studio has a major impact on the health and audio quality of your guitar?

When the humidity level is too high, the wood becomes too soaked in moisture, causing the instrument to warp and become out of tune. A low humidity level isn’t good, either. It can make your guitar dry and brittle, and its tone and structural integrity might suffer.

And that is why it’s important to maintain the ideal humidity level for your guitar.

Luckily, keeping your instrument at the right humidity level is simple. If you invest the time to monitor and control the humidity level in the space that surrounds your precious guitar, you should be able to enjoy playing your instrument for years to come.

In this post, we’ll discuss why a proper humidity level is important for your guitar. We will also go over a few ways to check humidity, and what you can do to keep your instrument sounding and looking its best.

The Ideal Humidity Level for Guitar

According to several sources like the Nashville MI Guitar Craft Academy, the ideal humidity level for a guitar would be between 40 and 55 percent. However, keeping it at 40 to 60 percent RH (relative humidity) is generally fine as well.

Similar to humidity levels for hardwood floors, these are the ranges at which the wood would be most stable and least prone to suffer issues due to changes in humidity levels. If the moisture content goes below 40 or 35 percent, the wood might become excessively dry. It can become fragile and susceptible to warping, shrinking, or cracking.

On the other hand, anything above 55 to 60 percent might cause the guitar to get too moist. This may cause it to swell and affect its playability.

Acoustic guitars aren’t the only ones susceptible to damages caused by bad humidity levels, though. Solid-body guitars and bass guitars are also no exceptions. They can be prone to the similar neck and cosmetic issues that acoustic guitars suffer from. It’s also important to control humidity levels for acoustic pianos.

It’s important to keep an eye on the humidity level in the space surrounding your guitar to make sure it stays within the recommended range.

Why Does It Matter?

The ideal humidity level matters for guitars because most guitars are made out of wood which is a hygroscopic material. This natural material reacts to its surrounding environment, and so does your guitar.

Too much moisture causes problems. But dehydration isn’t good, either. Your guitar, being made of wood, will respond when there are too high or too low levels of humidity in the air and changes in temperature. This will result in expanding or shrinking, affecting the overall quality of the guitar.

It’s important that you monitor the surrounding temperature, keeping it at 65 to 75 degrees Fahrenheit. You also need to store your guitar properly, which we will get into later in this post.

How To Identify a Wet Guitar

If your guitar has been exposed to extremely high humidity for several weeks or months, it will become over-humidified. Here are a few indicators that a guitar has too much moisture in it:

Warping and Swelling

Any twisted or bent parts of the wood may be a sign of a wet guitar. The neck can become misaligned or be at a weird angle. Too much humidity can also cause the top to become deformed.

When the wood of the guitar absorbs too much moisture from the air, it may become swollen. This will leave the frets higher than normal. It will also make the strings more difficult to strum.

Keep in mind that all guitars will have some sort of “bellying” behind their bridge. However, it does not necessarily mean that your guitar is wet or has too much moisture in it.


Some guitars include metal parts. If your guitar has metal-like strings or hardware, these elements may become rusty if exposed to excessive amounts of moisture.

The Smell

A musty or moldy odor on the guitar may indicate excess moisture in the wood. In addition, the wood may feel moist to the touch, or you may notice water droplets on the surface.

Sound Quality

A guitar with excessive moisture may sound dull or have less sustain. It may not stay in tune the way it used to, which might be an indication of high humidity levels.

Dehydration Can Damage Your Guitar

Dehydration means a low level of humidity in your guitar and it happens. While excessive moisture can definitely damage your guitar, dehydration can also be harmful to your instrument for a number of reasons.

For one, it can make the instrument fragile and susceptible to warping or breaking. Also, the guitar strings can get dehydrated and lose their elasticity, resulting in poor sound quality and shorter lifespan.

Symptoms of Low Humidity for Guitars

So, you already know that dehydration can do just as much damage to your guitar as excessive humidity. But how would you tell if your guitar needs some moisture? Here’s a checklist to help you detect hydration issues so you can address them before the worst-case scenario happens:

  • Warping or cracking
  • Noticeable damage on the finish
  • Guitar tops are contracting and sagging downwards
  • Lowered action and fret buzz
  • Narrower neck, but frets keep its width
  • Lifted bridge off the guitar top
  • Sharp fret tips protruding from the edge of the fingerboard as it dries out
  • Change in tone; sounds brighter or screechy

How To Protect Guitar From Adverse Conditions

Temperature affects the humidity levels there are in a room or where you store your guitar. The humidity level drops as the temperature rises because the air will hold more moisture. But when the temperature drops, the air can carry less moisture, causing the humidity level to go up.

You obviously have no control over such situations. But there are things you can try to protect your guitar against temperature changes. 

Store Your Guitar Properly

To keep your guitar safe from extreme temperature and humidity fluctuations, store it in a dry, well-ventilated place. Here are some viable storage ideas:

  • Avoid keeping your instrument in places that are moist or humid like your basement or a bathroom. Place in a room with excellent air circulation, instead.
  • Use a guitar case to protect your instrument from scratches, scuffs, and other sorts of physical damage. Doing so can also help keep your guitar dry if you have no choice but to store it in a place with a high humidity level.
  • Never expose your guitar to direct sunlight or other heat sources. Remember that too much heat can also harm the wood and finish of your instrument. The same thing happens when you store your guitar in a cold location.

In Case of Dehydration, Humidify Your Guitar

As you may already know, low humidity levels can do as much harm to your guitar as high humidity does. Humidifying your guitar is generally a good idea, especially if you live in a dry region or store your instrument in a dry location.

In this case, a guitar humidifier will come in handy. These are small water-filled devices that you insert into the soundhole of your guitar. It injects moisture into the air inside the guitar, helping to keep the ideal level of humidity. A room humidifier will also keep indoors at an ideal humidity level.

You may also want to consider getting a hygrometer. This device reads the humidity level in your home or the room where you keep your guitar.


Is 40% humidity okay for an acoustic guitar?

Yes. The ideal humidity level for an acoustic guitar is between 40 and 50 percent. However, keeping it at a 40 to 60 percent humidity level is generally acceptable, too. These ranges are considered to be safe and suitable for keeping the instrument in excellent condition.

At what humidity do guitars crack?

Low humidity is the most common reason why the top or back of the guitar cracks. Dehydration occurs at 35 percent humidity. If the level of humidity falls below that, it gets more damaging to the guitar.

How do I know if my guitar is over-humidified?

There are a few indicators that your guitar may be overly humidified. If the wood feels softer or more pliable than usual, there’s a high level of moisture in the guitar. Another indicator is the neck of the guitar. It will likely feel more flexible or “loose.” And it might also feel a little heavier than normal.

Check the strings. If they feel looser or get more easily out of tune, then it might be a sign that your guitar is over-humidified.

What happens if I don’t humidify my guitar?

Your guitar’s wood construction is hygroscopic in nature. This means that it absorbs and emits moisture from the atmosphere. The wood in your guitar can dry up and get brittle if the humidity in the environment is too low.

Since the strings are no longer pushing against a correctly tensioned neck, the guitar can quickly become out of tune. Your guitar’s neck could also become more susceptible to warping. This could impair its playability. And in severe cases, the wood may break.

Does a humidified guitar sound better?

As the wood absorbs moisture, it expands. This will cause the top of your guitar to expand as well. Acoustic instruments will also feel less reactive or dreary if they absorb too much humidity.

Although it’s not as damaging as being overly dry, a humid atmosphere can significantly impact the way your guitar sounds and plays.

How often should I humidify the guitar?

It depends on the temperature of your home or the space where you store your guitar. You must also consider the type of wood your guitar is made out of.

If you live in any region that gets very dry, has cold winters, or where RH typically hovers in the 20 to 35 percent range, you can humidify your guitar every 5 to 7 days. Solid wood guitars are more sensitive to humidity fluctuations. So they may have to be humidified more frequently than other types of guitars.


Keeping the relative humidity level at 40 and 55 percent is important to preserve your guitar’s quality and sound. Remember to store it properly, monitor the humidity level in your space, or invest in a humidifier. And make sure to not keep the storage space too dry for your instrument to avoid cracks and warping.

A little more work today will go a long way toward protecting the quality of your guitar in the long run. And if you haven’t already, get a hygrometer and monitor and adjust the humidity level in your guitar’s case. Your guitar will thank you later!

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