What is the ideal humidity for guitars? 

ideal humidity for guitars

How does humidity affect an acoustic/electric guitar, and what are the ideal humidity levels?

When your guitar is exposed to too low – or too high relative humidity levels, you are putting it at severe risk. 

But what is the ideal humidity for guitars?

The ideal humidity levels for guitars are 45-55%, but 40-60% is also acceptable. Avoid cracked bridges, shrinking fretboards, and other damage to your guitar by using a digital hygrometer to monitor the humidity levels.

If you’re not sure whether your guitar has been kept in the 40-60% range, you will definitely know after reading this post. Let’s look into what symptoms your guitar might have and what we can do to protect and repair it.

How do humidity levels affect your guitar?

Too low or too high humidity levels can seriously damage wooden instruments like acoustic guitars. 

When the air is hot, it can hold more water than when it’s cold. So, the humidity levels in your area are higher in the summer than in the winter.  

All of us know what the different humidity levels feel like. If you wear glasses, you have experienced that they get really foggy the second you step inside your house on a cold winter day. This is because once the cold air comes into the house and is heated up, the humidity levels relative to the temperature are lower.

So, we feel uncomfortable when the relative humidity levels are too low or too high. 

…and so will your guitar.

Ideal humidity for guitars: get a room!

Many guitar stores have dedicated rooms that consistently maintain humidity levels. Then, both the player and the guitar are happy!

Potential Damages to Your Guitar

Generally, an acoustic guitar is composed of wood, steel, and some plastic pieces, like the bridge pins (the pins that lock the strings to the bridge).

The steel components like the machine heads and strings will hardly be affected by temperature, but the wood can be severely damaged when temperature changes and the relative humidity drops or rises.

When relative humidity is below 40%

The air is too dry.

  • When the relative humidity is below 40%, the guitar top might start to sink in, which might cause the string action to lower as well. This will make your guitar much harder to play. 
  • The guitar body will get cracks.
  •  The fretboard will shrink.
  • The bridge can start to separate from the body and eventually just snap right off.

Two ukuleles without a bridge.

This has actually happened to two of my ukuleles. One of them was rarely used, so it was just placed in the window for a whole year. Eventually, one day I heard a large “CRACK!”… The bridge had snapped right off. 

My second ukulele was just hanging on the wall, right next to a radiator that was frequently turned on and off during the winter. One day, the bridge just flew right off.

When relative humidity is above 60%

The air is too wet.

  • The opposite happens. The acoustic guitar top will swell up, causing your string action to lift higher. This will also make your wet guitar feel harder to play.
  • If you have ever found an old guitar in the cellar, you might have noticed that the sound it produces is quite dull. This is due to the guitar being exposed to high relative humidity levels. In other words, don’t store your guitar in a wine cellar! 
  • Due to the swelling, the strings will eventually fly off. 
  • You may start to see mold on your guitar. Not recommendable. 

The strings’ distance to the fretboard can sink or rise if the guitar is exposed to low or high relative humidity.

How to measure humidity levels in your house

If you want to know the humidity levels in your house, you need to get your hands on a Hygro-Thermometer.  

This is a device that measures the humidity of the air. When you measure the humidity, try to walk around the room to see if the humidity levels are changing. Often times there are better conditions for your guitar in closets or away from radiators. So if you can, relocate your guitar to the spot where the humidity levels are within the 40-60% range. 

The highly reputable guitar brand Taylor offers both a mini version and a big digit version of the hygro thermometer:

The Mini: Good to keep in the guitar case along with your guitar.

The Big Digit: Good to keep in a room filled with several guitars.

How to protect a guitar from humidity

The best place to store and protect your guitar is actually to keep it in its guitar case. The hardshell cases to be more specificBut I’ll be the first to admit that I am very lazy with this myself. My guitar is being used quite often, so I like to have it on the guitar stand.

Having your acoustic and electric guitars on a wall mount or stand in the winter is not optimal. You see, when stored in a cold room, sudden hot air from radiators can cause the temperature to rise quickly, rendering the relative humidity too low. 

My guitar is mostly displayed on a stand. Right in front of my Pokémon stuff.

And thereby causing the guitars to find themselves below the relative humidity of 40%, which spells trouble.

Simple solution #1: Humidpak in your guitar case

You don’t need to spend a ton of money to protect your guitar and keep it in the sweet spot of 45-55% humidity level. 

You can just get your hands on the Humidipak from D´addarioThis will carefully adjust the humidity levels, regardless of whether it is too low or too high. This is called a two-way humidity control and will help you monitor the humidity levels surrounding your guitar.

This is an easy and effective way to maintain your guitar so it won’t be too dry or too wet. If you are storing your guitar in its guitar case, the Humidipak will make sure that it is always right in the sweet spot. Not only that, but it will also improve your guitar so it feels much better to play!

How to use a Humidipak in the guitar case:

  1. Put the Humidpaks inside the black pouches that come with it. These will need to get refilled once they feel like hard crystals.
  2. One goes underneath the little area below the guitar neck. This pouch will protect the wood in the neck area.
  3. The other one hangs between the G and the B string and down the soundhole, protecting the guitar body.
  4. Each pack will last between 2-4 months. 

The Humidipak costs so little compared to what you would have to pay to get your guitar repaired or having to buy a new guitar. Especially if you already have spent thousands of dollars on it. I wish I had done this sooner myself, but at least now I know!

Since it will provide moisture to a dry guitar it may even start to heal minor cracks. However, D´addario themselves does inform that it cannot fix severe cracks. And you should also re-humidify the guitar before using the Humidipak as a maintenance system.

You can check the current price of the Humidipak on Amazon if you are interested.  

Simple solution #2: room humidifiers

Do you have several guitars hanging on the wall in your room? Well, you might not wish to get a hardshell case for every single one. Or, you just really want them to hang on your wall, for anyone to see, whatever time of year.

Then you can take a look at room humidifiers.

If you have a room filled with guitars that might run the risk of drying out in the winter, this might be your solution. 

I recommend that you take a look at a room humidifier such as this one from Tumisue.

How to fix guitars damaged by humidity

After I began doing the research, I found out that my guitar was in fact a little too dry. It had been exposed to low relative humidity for too long. And whilst the Humidpak is good for maintaining the humidity levels, it won’t fix severe, permanent damage to your guitar. 

Luckily, there were not any big cracks that would need gluing. But I could see smaller cracks starting to form. 

However, it was not beyond salvation!

If your room has low relative humidity below 40%, chances are that your guitar has become too dry and major cracks may start to form. In order to restore the moisture of your guitar and to allow the guitar to expand its wood to seal cracks, you need to get a humidifier


  • It can be a little tank filled with distilled water. The Oasis Humidifier is a great option. You fill it with water and put it underneath the strings over the sound hole. This humidifier will create a chamber of humidity, constantly providing humidity for your guitar. 
  • Or it can be a sponge, like the D´addario Acoustic Guitar Humidifier. Soak the sponge, twist it, and put it in a black cage that comes with it. This is placed between the strings over the soundhole. If the sponge is completely dry after the next day, soak it again and repeat until some water is still left in the sponge. Now you know that your guitar has absorbed the amount of moisture it needed. Yay!

Humidifying your dry guitar with one of these products will do wonders, so give this a try before taking your guitar to the repair shop! You can check the price of the Acoustic Guitar Humidifier on Amazon.

If you are worried about putting objects filled with water through the soundhole: don’t worry! Both methods are considered safe for your guitar.

This is a process that may take several days. But by the end, you will be amazed b what this solution can do to your guitar. 


When it is the other way around; when your area has high relative humidity above 60%, your guitar is probably too wet and swelling of the guitar top will happen. Then you must get a dehumidifier.

It consists of material that absorbs moisture from the guitar. For example, the Guitar Humidifier Set from Taylor Guitars is made of Bamboo Charcoal, which attracts excessive moisture from the guitar.

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Thomas Leypoldt

Hey there! My name is Thomas and I have been a film composer for over 10 years, delivering music to feature films, documentaries, video games, and commercials. I share everything I have learned on this website, to hopefully be of help to your own development as a musician.

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