Storing tires (or any other rubber items) outside is a recipe for disaster, at least in terms of longevity, unless they are vacuum-packed, sealed air tight, and protected from direct sunlight & wide temperature changes....
And these things really won't do your rims any favors either....
But the #1 thing to do first: thoroughly clean & dry them for at least 24-48 hrs before storing them !
When I had to store a set of tires w/rims in my shed from another vehicle, I wrapped them in some
very heavy black plastic sheeting (I believe it was 16mil thickness, which is the equivalent of about 5-6 really heavy duty commercial trash bags in one layer), pulled together at one end to make a long twisted "handle", injected some silicone caulking into the twisted part, then twisted them even tighter & secured them with very several heavy-duty black zip ties. Then I wrapped them with a 2nd piece of the black sheeting and duct taped the crap out of it....
And 1.5 years later when I sold them, they were still like brand new and had the same 36psi of air in them
I feel like this would have
probably worked even if they were stored outdoors, but I had the room in my shed & didn't want to take a chance on ruining them...
