There are different considerations in each case. But in the end, the best advice is the same: It's best to store golf clubs in a dry, temperature-controlled environment.
Day-to-Day Golf Club StorageSo you're not worried about storing golf clubs for a few months, you're just wondering about storing them for a couple days until your next round of golf. And you don't want to lug them back inside your house. Can't you just leave them in the trunk of your car? Or at least in the garage?
Car trunk: We recommend that you never leave golf clubs stored in the trunk of a car. If it will be a few days before you play golf again, then you'll be driving around with the clubs back there, clanging about, possibly picking up scratches or nicks or dents.
Heat is another reason to avoid the trunk. Temperatures inside a car trunk can climb close to 200 degrees on hot, sunny days. Clubmaker Tom Wishon says that at those temperatures, the epoxy affixing the clubhead onto the shaft can break down over time. The glue under the grip can also break down, causing the grip to slip around the shaft. Now, maybe your clubs won't be in the car trunk long enough for such a breakdown to occur. But why take the chance? Besides, you don't want your clubs banging around in the trunk. So take your clubs out of the trunk when you get home from the golf course.
Garage: If you want to leave your clubs in the garage overnight because you're using them again tomorrow; or store them in the garage for a couple days until you need them again, that is fine. Just make sure your clubs and bag are dry - always dry off golf clubs and make sure the golf bag interior is dry before storing them, whether for a day or a year.
If moisture tends to build up in your garage, then take your clubs inside your home. High-humidity can lead to rust. Heat build-up in garages doesn't reach the same temperatures as it does in a car trunk, so epoxy and resin breakdown shouldn't be a problem.
But again, make sure your clubs and bag interior are dry before leaving them in the garage for a few days. If you won't be using the clubs for another few days, it's always a good idea to clean your clubs (including cleaning the grips) and wipe down the shafts before storing them.
Conclusion: Don't leave your clubs in the car trunk. The garage is fine for a few days at a time so long as your clubs are dry and clean. But if you want to be absolutely sure your clubs are stored well, bring them into your house or aparment, clean them and dry them off. Inside your home, there is no chance of heat affecting grips or epoxies.
Long-Term Golf Club StorageWhat about long-term golf club storage - for several months or more? Maybe you're putting your clubs away for the winter; maybe an illness prevents you from playing; or other long-term obligations make it clear you won't be needing your clubs for a while. How do you store golf clubs for several months or more?
Forget about the trunk of your car. Get those clubs out of there!
A garage or storage facility? If the location is humidity- and temperature-controlled, yes. Otherwise, no.
For long-term storage, bring those golf clubs into your home, or put them in some other interior location that is dry and temperature-controlled.
Before you store golf clubs over the long term, give them a cleaning. Clean the clubheads and grips and wipe down the shafts. Let them completely dry before placing the clubs back in the golf bag. (And make sure the interior of your golf bag is dry before replacing the clubs.)
If your golf bag came with a rain cover, place that cover over the top of the bag. And then find a corner of a closet or a room - some place out of the way where the bag won't be getting knocked around - and put the clubs away.
If your garage is not temperature-controlled, then don't store golf clubs there over a winter. Constant exposure to cold won't damage the clubhead or shaft, but could dry out the grips and cause them to harden or crack.
Once again, the most-important things to remember about how to store golf clubs:
1. Make sure they are dry before you put them away.
2. If putting them away for more than a few days, clean them first.
3. And keep them in a dry, temperature-controlled location - inside your home is always the first choice.