It's a little late now, like closing the barndoor after the horse gets out, but you should consider getting a humidifier. I got a Vornado room humidifier for about $50 from Amazon. I keep my bass in a small room, so the Vornado works well (the room size is like a small bedroom or a bathroom -- about 10ft x 10ft or so). I had used it in a larger room that was twice the size of my present room, and it didn't do the job of keeping the room humidified. So, if you have a smallish room to keep your bass in, get a humidifier and save those cracks.
Mike