GoKawiilHard drives contain lots of moving parts and delicate electronics, which means they're sensitive to their environment. Extreme heat can damage internal components and degrade the drive's lubricants, while humidity poses the risk of corrosion on circuit boards and connectors. Meanwhile, magnetic fields can interfere with the drive's platters and corrupt stored data.
Even when stored well and never touched, drives aren't 100 percent safe because mechanical components can seize up from long-term inactivity. Similarly, capacitors on the circuit board can simply degrade over time. That's why what you do with the drives matters along with the storage conditions.
Before a drive goes into storage, treat it as if it could fail the moment you put it away. While this is a grim way of looking at it, no storage method is completely foolproof. Copy any important files (especially irreplaceable ones like pictures and videos) to another location, and ideally, back them all up to a cloud solution. For any critical data, consider making a second physical backup copy and storing it somewhere else, like a safe deposit box or a family member's home. That way, the data is protected against natural disasters and theft. Test everything to confirm the data transferred correctly before you archive the drive.
While it's commonly cited, the 3-2-1 rule of backup is still helpful: three copies of your data, on two different storage mediums, with one of them offsite. Copying whatever is on your old drives to your current PC, then backing it all up with a cloud tool, is a decent way to satisfy this.