How and When to Humidify Your Ukulele

By | April 8, 2015

Solid wood ukuleles sound great, but they also need to be kept from completely drying out. Natural wood needs a certain level of moisture to stay structurally sound – no pun intended. Without it, your ukulele can warp and crack. While this is by no means a certainty, not using a humidifier is a gamble you don’t want to take with your more expensive solid wood ukulele. So how does this work, and how do you know when your ukulele needs a humidifier?

When to Use a Humidifier

Depending on who you ask, you’ll hear that humidity levels below 35% or 45% can be dangerous to acoustic instruments. This guideline refers to relative humidity, which is defined in terms I do not understand over at Wikipedia. Suffice it to say, it’s a metric reported along with most weather reports. Unfortunately, you can’t rely on the relative humidity provided in a weather report unless you keep your instruments outside.

There are two typical conditions that lead to low humidity in the home. The first is that you live in a naturally arid place like a desert or high mountain region. The second is that you live in a cold climate and the heat in your home sucks all the moisture out of the air. For example, I’m in near Boston, Massachusetts in early April. According to, current relative humidity is 77% – it’s been a rainy day – but inside my house it’s only 33%.

For this reason, it’s important to pick up one of these:


This is a little device called a hygrometer that goes right in your ukulele case and keeps an eye on what the relative humidity is for your ukulele. When you see that number on the right go down below 45%, it’s time to start using a humidifier. The batteries in these things last seemingly forever, so they’re very low maintenance.

How to Use a Humidifier

Oasis has owned the market on ukulele humidifiers for some time, and for good reason. There are other options, but none compare to the oasis for ease of use, performance or cost. The Oasis ukulele humidifier is a little cloth tube with water-absorbing beads inside. You fill the tube with water and the beads retain the water so that it is released slowly. The cloth around the tube features special pores that let water vapor escape, but not water. You definitely don’t want water spilled in your ukulele while its in your case – I’ve used a few of these humidifiers for years and have never seen a drop of water come out.

The humidifier hooks in between the C and E strings of your ukulele and remains suspended in the sound hole, like this:


The only mile hassle here is that the ukulele needs to be kept in its case, and on its back. If you pick up the case and flip it around with the humidifier in like this, it can come loose and fall into the body of your ukulele. That’s not a tragedy, but getting it out will be a bit of a pain.

Keeping the ukulele in its case as a matter of habit is a pretty serious downer for me, which is why I ended up buying a laminate ukulele to hang on the wall during the winter.

About once a week, the humidifier will start to run out of water and shrivel up. This shriveling up is a nice and simple indicator that you need to add more water.


The humidifier comes with a plastic syringe to help fill it up without accidentally soaking it with water. If you overfill the humidifier, the water-absorbing beads will float to the top and spill out, so do use the provided syringe.

And here’s another photo after I filled it:


Humidifier Maintenance

About once a year, you should replace the water-absorbing beads inside the humidifier as they start to lose their absorbance. Amazon sells the Oasis Humigel Replacement Kit for about $6.

You can also pick up the Oasis Ukulele Humidifier and the Oasis Hygrometer at Amazon.

2 thoughts on “How and When to Humidify Your Ukulele

    1. Matt Post author

      That depends on what you mean by “normal humidity”. As stated above, if the humidity in the room is much below 45%, you’re running the risk of damaging the instrument. If the natural humidity as measured in the room where you keep your acoustic instruments is consistently above 45%, then there is no need to humidify your instruments.


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