Ideal Humidity Levels For Guitars/Musical Instruments

What is the ideal humidity level for guitars or other musical instruments? The optimal relative humidity levels for guitars is 45-55 percent, but if you are in the range of 40-60 is acceptable.

An Acoustic Guitar In Good Working Condition

The thin back, sides, and top of the semi-hollow body of acoustic guitars are the parts most prone to rapid changes in temperature and humidity.

However, any type of musical instrument can get damaged when it is kept outside its safe zone for a long time.

Once conditions go beyond this range, you risk causing damages on your guitar.

Whether you believe it or not, your beloved guitar still considers itself a tree. Yes, that’s true. Similar to a tree, it is natural for guitars to acclimate to any environment they get exposed to. If this environment goes beyond the ideal range, this could mean disaster.

So far, air humidity is the most harmful silent guitar killers that not a lot of people even know or think about.

To make it simple, a guitar is made of wood and this is the reason why it reacts to the environment it is in.

Humidity is only among the factors that can make the guitar wood deform. The extent of the damages the humidity can cause will vary depending on the humidity amount.

In extreme situations, a guitar can get totally unplayable.

But, the unnoticeable damage is the most dangerous of them all. When you put your guitar in an area that is either too humid or too dry, it will start to react little by little.

Often, this reaction is just a subtle one and the sole way for you to notice this is to carefully check and inspect the instrument. Just a few people bother to do this kind of inspection, at least not that often. Humidity can react to different kinds of guitars.

For instance, an electric guitar will not suffer too much from humidity compared to an acoustic guitar. Having said this, any guitar is always at risk.

A hygrometer is the best instrument you can use for monitoring humidity. A hygrometer is a type of device that can measure air moisture. Keeping a hygrometer inside the case of your guitar and checking it every now and then will let you know if the guitar is too dry or too wet.

It is also important for your case to have its humidification system for regulating humidity. It means that if you don’t use a humidification system, it can drastically increase the risks of harming your instrument.

Humidity damage is so far the most common issue that many guitar owners face, particularly during winter months.

Your home’s heating system has been designed for circulating dry and warm air. Sadly, this also makes the perfect recipe to dehydrate guitars.

See to it that when the months of winter kick in, use a humidification system that can help prevent damages not just on your guitar but also on other instruments.

Guitars and Instruments with Frets

For guitars and other types of fretted instruments, shops will maintain the level of humidity at around 50%. But, this level can be quite comfortable in a home. You have to maintain the level of humidity in the room at around 35% to 50%.

However, even at 35%, you may still notice some form of shrinkage in the tops, with the frets starting to protrude. Your instrument is going to be better if you can maintain a relative humidity of 50%.


Improper levels of humidity can easily damage a piano. Extreme levels on both sides can spell trouble. It is best that you maintain the room’s humidity level at around 40% for optimal conditions.

Direct heat sources and sunlight can also lead to issues for the piano so it is always best that you keep it away from these.

Improper Storage and Its Dangers

Everyone loves showing off their guitars, putting them on display on an area where others can adore and admire them. However, the safest spot for storing your guitar is actually in its own dedicated case.

If you don’t have plans to strum anytime soon, a hardshell is going to protect your instrument from rapid changes in humidity.

It is easier to maintain and control humidity in a smaller space. Provided that you use a hygrometer for monitoring the case’s interior, you can keep a keen eye on the environment of your guitar all the time.

The risks of storing your instrument on a stand are not just about causing an unwanted tumble as this also risks exposure to direct heat and dry air from fireplaces, heating ventilation, and radiators.

Wall hangers are dangerous as well since the guitar’s back part will acclimate to the temperature of the room, with the top acclimating to the temperature of the room.

During the winter season, temperatures are not consistent at all times. The variance can cause the guitar to contract and expand at varied rates and will lead to failed joints, severe playability problems, and cracks.

Is High Humidity Bad For Guitars?

High humidity can also have an impact on the playability of a guitar. Most guitars are built with a fingerboard that has a small amount of relief or forward bow. This is what it is called if the amount is right or otherwise, it will be the warped neck. When humidity gets too high at 70 percent or higher, the expansion differential between the neck and fingerboard woods can make the fingerboard lose its relief or even form some amount of back bow.

Probably the number one most exasperating concern when caring for your high-quality guitar is the possibility for the wood to expand or shrink with the constant changes in humidity.

You can avoid expensive and unnecessary repairs through having a better understanding of the effects of humidity changes and through applying several available simple remedies to deal with them.

These days, almost all cheap guitars are created using plywood. In spite of being mediocre as a type of tonewood, plywood is durable and reliable and can withstand considerable abuse from the atmosphere.

On the other hand, high-quality guitars are created using solid wood all throughout. This is the reason why these guitars sound much better compared to cheaper instruments. However, solid woods are more prone to changes in the humidity since they expand and shrink more compared to plywood.

Once humidity gets too high, the guitar might sound a bit soggy. It will lack projection and volume and its tone will be dull and lifeless. It is also very possible that the guitar will suffer from structural damage once the humidity is too high.

The most common issue is bloating in its back part, particularly when the back is made from rosewood or other kinds of very hard wood. It is due to wood expansion and specifically changes in back to brace glue interface. There are rare cases wherein the condition can result in a back to brace glue joint failure.

The condition may develop quickly after the guitar is exposed to an environment with high humidity. The smallest amount of back bow may cause considerable adjacent-fret buzzing. But another issue that may be due to very high humidity level as in a damp basement or in tropical areas is the glue’s deterioration and even the wood.

The effects of low humidity are a common issue in the world’s temperate regions and these are a serious problem. Loss of extreme moisture in tonewoods sometimes makes guitars sound plinky or brittle even if it might seem to have nervous and peculiar liveliness. At a critical point, accumulated stress brought by uneven wood shrinkage will relieve itself through producing cracks and glue joint failures.

The primary concept to understand humidity is what the meteorologists call RH or relative humidity. It basically refers to the ability of air for taking on and retaining water or drying out the moisture-containing objects it surrounds. If the temperature of the air is high, the more water it’ll hold before precipitation and saturation occurs.

RH is the amount of the moisture present in air expressed as the percentage of the moisture that the air can hold and that certain temperature before the process of precipitation happens. It is actually humidity relative to the temperature. If RH is 40%, the air once maintained at constant temperature will hold 59% more moisture before the precipitation process occurs. As the level of humidity increases, the air will take on additional moisture. Once relative humidity decreases, the air will accept more moisture quickly.

How to Achieve Ideal Levels of Humidity For Your Guitar

You will need some kind of humidifier to influence humidity . It is a type of device that can regulate the humidity levels and allow you to maintain ideal values all the time. You can find three types of humidifiers available in the market today, each of which gives you a unique kind of result.

A room humidifier is the first common type. This device can alter the humidity of an entire room. But, in general, this is not the perfect solution unless there is a special room dedicated especially for storing your instruments.

A more localized method to maintain optimal humidity levels is through using a soundhole humidifier. This is a type of device inserted into the acoustic guitars’ sound hole that can deliver optimal humidity levels.

The last and possibly the most effective type of humidifier for guitars is the guitar case dehumidifier. This is inserted into the guitar case and often works best since it can control a well-defined area.

Almost all humidifiers will require some water. Generally, you have to add water every 2 to 3 days.

Some of the more modern humidifiers have the ability to detect if the humidity is taking a very low dip as well as if it goes beyond the optimal values.

These can then regulate the environment either through removing the excess humidity or adding more until the ideal levels have been achieved.

Either way, it is always best to use a humidifier and hygrometer together. Simple as it may seem, the hygrometer can measure humidity that lets you maintain the best humidity levels all the time.

The Bottom Line

Dealing with the humidity levels is something you have to add to your usual maintenance routine for your guitar whatever its type may be.

It is among the most overlooked reasons why guitars get damaged and something that you can actually prevent with the use of the right tools.

If you wish to prolong the life of your guitar, specifically the pricier ones, a humidifier is not just a great investment for it is also something every guitar owner like you should have.