Most guitar care advice focuses on the risks of cold, dry winter air. But summer brings its own set of challenges — high temperatures, UV exposure, humidity swings, and the particular hazard of leaving a guitar in a hot car. Here's what to watch for and how to protect your instrument through the warmer months.
The Heat Risk: Glue Joints
The most serious summer risk for guitars is heat damage to glue joints. Traditional hide glue — used in many acoustic guitars and vintage instruments — softens at relatively low temperatures. A guitar left in a car on a warm day can reach internal temperatures well above 50°C, which is enough to soften hide glue and cause braces, bridges, or even the top to come loose.
Never leave a guitar in a parked car in warm weather. Even on a mild day, car interiors heat up rapidly. This applies to both acoustic and electric guitars — while electrics are less vulnerable to glue joint failure, extreme heat can warp necks and damage finishes.
UV Exposure
Direct sunlight fades guitar finishes over time and can cause nitrocellulose lacquer to check or craze. Keep guitars away from windows and out of direct sunlight, both in storage and when displayed on a wall.
For added protection, applying a finish-safe polish or wax creates a barrier that helps shield the lacquer from UV degradation. The following LORE® products contain UV protective compounds and are formulated specifically for instrument finishes:
- LORE® Instrument Polish 100ml — a fine polish that cleans and protects, leaving a UV-resistant barrier on lacquered and poly finishes.
- LORE® Microcrystalline Wax — a hard-wearing protective wax that seals the finish and provides long-lasting UV defence.
- LORE® Fingerboard and Body Wax — a dual-purpose wax suitable for both the body finish and unfinished fingerboards, with UV protective properties.
Humidity in Summer
In the UK, summer humidity is generally higher than the 45–55% target range for guitars. Sustained high humidity can cause swelling of wood (particularly on acoustic tops and necks), glue joint stress from expansion, and mould growth in cases and on unfinished wood surfaces. If you're in a particularly humid environment, a dehumidifier in the room or silica gel packs in the case can help maintain the target range.
Travelling with a Guitar in Summer
By car: Never leave the guitar in the car. If you must transport it, keep it in the passenger compartment with air conditioning running, not in the boot.
By air: Guitar cases in aircraft holds experience significant temperature and pressure changes. A well-padded hard case is essential. Detune strings slightly to reduce tension during the flight.
On foot or by public transport: Keep the guitar in a shaded bag or case, out of direct sunlight. Allow it to acclimatise before opening the case if moving from a hot exterior to an air-conditioned interior.
Post-Summer Check
At the end of summer, before the heating season begins, it's worth doing a full check of your guitar: check neck relief, check for any finish lifting or checking, clean and condition the fingerboard, polish the body, and check and replace humidity control packs in the case.
Summer guitar care is mostly about avoiding extremes — extreme heat, extreme UV exposure, and extreme humidity. Keep the guitar out of hot cars, away from direct sunlight, and in a case with appropriate humidity control. A quick check at the end of summer sets you up well for the drier months ahead.
Protect your instrument with the full LORE® range — petroleum-free guitar care, crafted for players who care about their instruments.
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