Hello,
In general at work we attribute blossom end splitting to too much water. If you get cracking near the stem or along sutures, that is genetic.
Thanks
Jonny

I was ready to hear about your spitting cantaloupes! :)

I'm thinking you are waiting too long to harvest them. Maybe they're just like cherry tomatoes that split if you leave them too long. Sometimes, especially after a good rain, they take in alot of water, and it puts a ripe fruit over the edge and they split. (But then again, that's nature working, 'cause it means its time for some animal to eat them and spread the seeds).
Looks like you should be eating cantaloupes a little sooner.

All of the rain we've been having here this summer has been a blessing. And a curse of splitting melons.

Thanks for your answers.

Another question. When exactly is a cantaloupe ripe. I wait until all of the green has gone away. Is this waiting too long to pick them?

What variety melon? Muskmelons, which Americans call cantaloupes, will easily detach from the stem when they're ripe. Just hold the cantaloupe and gently push where the stem attaches to it with your thumb. If it detaches easily, the melon is ready to eat.

Other melons aren't as easy. You can usually tell if they're ready by the changed color and often the fragrance.

The type of splitting you are describing is very common in netted cantaloupes. In this variety, when grown with very fertile soil, the cantaloupe isn't fully ripe until it splits as you describe. If you check them everyday they won't rot.