Cherries go moldy after raine when ripping.
As cherries begin to ripen they become susceptible to rain cracking. Through osmosis ripening cherry fruit absorbs water and begins to swell. When the fruit swells to the point that the skin of the fruit can no longer expand, they split open. Once the cherries split open disease organisms gain access to the fruit and cause the cherries to rot. Eventually, these rotted fruit may fall off the tree. This is the same problem that commercial growers have when rain falls on ripening fruit. Unfortunately, there is little that a home owner can do to protect fruit on a large cherry tree. Commercial growers will often cover dwarf cherry trees with plastic to keep the rain off of them, but this is not possible for a home owner with a large cherry tree.