Humidity and Guitars: Why It Matters and How to Protect Your Instrument

Humidity might seem like a small thing — but for guitars, it can make or break your tone, playability, and long-term value. Whether you’re storing a vintage acoustic or gigging with your electric every weekend, knowing how humidity affects your guitar is key.

Radnor Guitars in Nashville sees weather-related damage all the time. Here’s what to watch for and how to protect your instrument year-round.

Why Humidity Matters for Guitars

Guitars are made of wood, which naturally expands or contracts based on how much moisture is in the air.

• Too little humidity = wood dries out and cracks

• Too much humidity = wood swells and warps

This can affect:

• Neck stability and relief

• Fret sprout or sharp fret ends

• Glue joints (especially in acoustics)

• Top and back separation

• High or low action

• Finish checking or bubbling

Ideal Humidity for Guitars

45–55% Relative Humidity (RH) is the sweet spot.

Below 40%? Your guitar is at risk of drying out.
Above 60%? You’re risking swelling, warping, and mushy tone.

In Nashville, that means:

• Winter: Dry indoor air = risk of cracks

• Summer: High humidity = risk of swelling

How to Protect Your Guitar from Humidity Damage

Use a Room Hygrometer

Track RH where your guitar lives. You can get accurate ones for $10–$20.

Humidify in Winter

If RH drops below 40%, use:

• Soundhole humidifiers (like D’Addario or Oasis) for acoustics

• In-case humidifiers for electrics

• Room humidifiers if you keep multiple guitars on stands

Dehumidify in Summer

If RH climbs above 60%:

• Use silica gel packs in your case

• Keep guitars in climate-controlled rooms

• Use a room dehumidifier if needed

Keep Guitars in Their Case

A hard shell case protects better than open air. It keeps humidity fluctuations gradual, not extreme.

Signs Your Guitar Is Being Affected

• Fret ends feel sharp? Likely too dry

• Action suddenly higher or lower? Neck swelling or bowing

• Finish cracking or bubbling? Rapid moisture change

• Acoustic top has sunk or swelled? Wood reacting to humidity

If you spot these signs early, a professional setup or adjustment can often fix it. If left untreated, it can mean serious repairs.

Need a Repair or Setup? We Can Help.

At Radnor Guitars, we:

• Repair cracks and warped tops

• Reset neck relief caused by climate changes

• Recommend the right humidification system

• Offer seasonal setup adjustments to match Nashville's weather shifts

🎸 Want to keep your guitar playing and sounding great all year long?
👉 Contact us or stop by the shop — we’ll check your instrument’s condition and help you protect it.