Well, my ABI is fine. I've had it for over a year now, and I haven't seen any shrinkage. Well, I haven't been looking, but I haven't noticed any. No fret sprouting either.
If you live on the coast, then you should have about the same weather as me (maybe a bit warmer).
It's mostly been kept indoors, temps ranging from maybe 15 degrees C to 25-30 C tops. I don't have a moisture meter, I'm not that anal...

But it hasn't been poolside, or in very dry enivonments or anything.
The few times it's been outdoors it's been on the way to my car, or in the boot/trunk (pick your favourite(/favorite). It doesn't get very warm here in west coast Norway, but it's been outside in -15C for maybe an hour total.
EDIT: By the way, I like the new(?) "a new post has been made while you were writing, you may want to review your post"-function...