I have tons of never used electrical components like resistors, capacitors, coils, transistors from 10 years back and tons more of my fathers stuff (made in the Soviet Union) from 20..30+ years back.
They've never had anything rain on them, but they've spent only 4 years of that total time in a heated house and then went back into a shed.
Most of the resistors, capacitors and coils are in matchboxes or bigger cardboard boxes and most of the transistors are luckily packed in waterproof (and airproof?) plastic. All of the smaller boxes have been packed tightly into larger non-weatherproof cardboard boxes.