Tires: How long does it take for tires to dry-rot, weather stress, honda odyssey

Question
I bought a second-hand 04 Honda Odyssey in August and the vehicle was inspected by the dealer.  Here I am in Mid-November and our service garage informed us that the tires are dry-rotted.  We have not reached even 36,000 miles on our vehicle (we bought it at 29,000 mi.)  Does it make sense that this problem has shown up now and not 4 months ago?

Answer
Tim,

I'm going to make a distinction between dry rotting and weather / stress cracking.

Dry rot is a phenomenon where the rubber gradually detriorates on the outside simply by non-use.  The interior of the tire also slowly deteriorates, but at a lesser rate.

Weather / stress cracking is what we are discussing here and this all depends on how well maintained the tire were.  Extremely poorly maintained tires can show cracking within days of first usage.

So it's possible that the previous owner did not do a good job of maintaining the vehicle and in the 4 months you've owned it, the tires are now starting to show the affects of this previous abuse.

But just to be sure, I'd have someone who doesn't have a stake in your buying tires look at them.