Well, I'm in NJ. "The Garden State" ;) It rains alot throughout the summer up here, and the temps are basically 75-85 with your tedious days popping up here and their.
Anyway to my knowledge splits are usually due to the plant storing the water into the fruit, the skin being tight and the fruit bursting.
If you think about it this way the tomato itself is really just a shell for the seeds in order to reproduce the plant. So in all actuality it's doing what it's designed to do. Absorb the water, Split, fall to the ground, rot and feed the seedlings. Hence re-producing the plant. I believe this is all done because of an abundance of water.
Reason being is that if the ground isn't moist then the seedling may not be able to sprout into the dirt. So the over-watering is basically just a signal to the plant. Maybe?
Just my theory. Shoot me if i'm wrong. ;)