Having a wooden stringed instrument requires some attention to the humidity levels where it is kept. Too much humidity can cause swelling and lead to a number of problems. But too little humidity can be much more scary. It can quickly cause detrimental effects, namely cracking of the wood.
While some people would think that a smaller instrument needs less humidification, you have to consider that the panels of wood on an ukulele are thinner than almost any other instrument. On top of that, the best instruments are often built lightly for resonance which can be all the inspiration and tones you need, but can also require even more regulation of humidity.
So the first step is to know what your humidity is. In this regard, note what Dave Hepple from Oasis points out
Because relative humidity varies so much, even inside your home, we recommend that you keep your hygrometer close to your instrument.
What is closer than the case in which it lives? Oasis came up with a pretty good system to get a reading of what the humidity is right at the body of your instrument. This is the Oasis Hygrometer Kit OH-2. With your ukulele flat in its case, this hygrometer is thin enough to set on the top of your ukulele, over a piece of cloth so it doesn’t scratch the finish. Shut the case, but don’t move it around because the hygrometer might slide around. Just leave it flat for at least four hours. Now when you open the case, be ready to look at the hygrometer. You only have a few seconds to see what the humidity was before you opened the case. A well-humidified ukulele in its case will have relatively stable humidity readings, so you don’t have to measure the humidity all the time. But it comes with a clip and you can clip it in your case all the time.
So… once you get the reading what should you do? If your humidity is over 40% and under 65% you are fine. If your level is lower than 40% then you need to take action. If you are not currently using a humidifier then you should be. There are many ways to humidify an instrument but we chose the Oasis humidification system because we think it’s the best solution on the market. Other ones we have tried had leaking issues or were not as effective. If you’re anywhere from 25%-40% our standard Oasis OH-18 should work well and with your hygrometer you can measure that and make sure. We are now offering a more powerful humidifier and for those with 25% or less relative humidity where the instrument is stored for any period of the year it is needed. The Oasis OH5+ will emit more humidity to your instrument and we had them make it with the ukulele clip attachment. If you are currently using a humidifier and still are not above 40% in the case, consider switching to or supplementing with this humidifier.