A violin or viola is made of wood held together with glue, and wood reacts to the air around it. North Carolina gives it plenty to react to: humid summers, dry heated houses in winter, and quick swings in between. Here is what the weather does, and the habits that protect your instrument.

What humidity does to wood

Wood takes in moisture from the air and swells, and it shrinks as it dries. A violin's top is usually spruce, and its back and sides are usually maple. The two woods swell and shrink at different rates, so a big change in the air puts stress on the whole instrument.

The glue in a violin is meant to give way before the wood does. When the wood moves too far, a seam (a glued joint where the top or back meets the sides) can come open, and a repairer can glue it again. A crack in the wood is a bigger repair, and wood that gets too dry will eventually crack.

The weather shows up in other ways, too:

  • The pegs that the strings wind around can lose their grip after a big change in the weather, so you open the case and find a string loose. In humid weather a peg can swell until it will not turn.
  • The sound can change. Too much moisture can make the tone mushy and the instrument sluggish to play. Too little can make it feel tight, with a scratchy, harsh sound.
  • The strings can end up sitting higher above the fingerboard, where your fingers press them down, or you may hear a buzz.
  • Bow hair shrinks in dry air and stretches in humid air, so the bow needs a different amount of tightening as the seasons change.

How much humidity is right

Relative humidity is the amount of moisture in the air compared with how much it could hold at that temperature. A small gauge called a hygrometer measures it. The little gauges built into some cases are often inaccurate.

Museum conservators who care for wooden objects commonly aim for about 40 to 55 percent relative humidity, and they try to keep it from swinging from day to day. Advice for string players is similar: about 35 to 60 percent, depending on the source. The level should also stay steady. An instrument can adjust to dry or humid air given time, but quick changes cause trouble.

When the Library of Congress received five Stradivari instruments in the 1930s, the donor's gift also paid for a climate-controlled room to house them.

If the air at home drops below about 20 percent humidity, a room humidifier can help, but go gently. Too much added moisture does more harm than none, and a case humidifier can grow mold.

What North Carolina's seasons bring

North Carolina has a humid climate, with very warm summers and moderately cold winters. In July 2025, Greensboro recorded its warmest average low temperatures for any month on record. A big reason was the high humidity, as moisture flowed in off the Gulf and the Atlantic.

Winter brings the opposite problem indoors. When cold outdoor air is warmed inside, its relative humidity drops, and running the heat dries out the air in a house.

The changes can come fast. A North Carolina winter can run from frigid to spring-like, sometimes only days apart. The winter of 2025 to 2026 went from an early December chill to record highs in the 70s on Christmas Eve and Christmas Day. Summer has its own sudden change: stepping from an air-conditioned room into the heat outside.

Never leave it in a parked car

A closed car heats up fast. The temperature inside can climb 20 degrees in as little as 10 minutes and 50 degrees in an hour, even when it is only in the 70s outside. On an 80-degree day, it can pass 100 degrees within 10 to 15 minutes.

Heat like that weakens the glue, strong sun can melt the varnish, and an instrument can be badly damaged in a short time. A very cold car is risky too. Take the instrument inside with you, in every season.

Everyday habits

  • Keep the instrument in its closed case when you are not playing. The case slows down changes in temperature and humidity.
  • Keep the case away from radiators, heating vents, and sunny windows, and out of the path of air blowing from a vent.
  • When you bring the case in from the cold, let it sit closed for a few minutes. Then open it, but leave the instrument covered for another five or ten minutes before you play.
  • Wipe the rosin dust off the instrument, the strings, and the bow stick with a soft cloth each time you finish. Our article on rosin explains what it does.
  • Loosen the bow hair before you put the bow back in the case.
  • Do not touch the bow hair. Oil and dirt from hands spoil it.
  • Keep spare strings in the case. Our article on spare strings covers how to store them.

When to see a repairer

Now and then, look at the bridge (the wooden piece the strings stretch over) from the side. It should stand straight. If it leans, ask your teacher or a violin repairer to adjust it. Our article How to Tune a Violin or Viola explains why a bridge can lean.

Take the instrument to a qualified violin maker or repairer if you see a crack or an open seam, hear a new buzz or a rattle, notice the strings sitting higher than usual, or find a peg that will not turn. Do not try to glue anything or force a stuck peg yourself.

If you have questions about caring for your instrument, we are happy to talk.

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