First, do a backup. But do not store it with the computer.
Get yourself a large, plastic storage bin and place everything inside. Throw in some desiccant packs and run a bead of silicone sealant around the top of the bin before you close it for the last time.
It will be air tight so you don't have to worry about condensation when the temperature changes. It will be virtually critter proof (ants, spiders, hornets, rats eating cables, etc). If the storage facility experiences weather damage or flooding, you're covered.
When you retrieve your computer, let it come to room temperature before you open the bin. Clean it out, check the seating of cards, memory, etc.
It should be fine.
pretty nice answer. – JoséNunoFerreira – 2011-06-16T14:24:39.987
3+1. If I had to store electronic equipment outside, this is the way I'd probably do it. Thanks for the good advice. – joeqwerty – 2009-12-16T01:18:13.653