Why do my tomatoes split open right before they are ripe?
Certified GKH Gardening Expert
This usually happens with uneven moisture. When it is hot and dry for a period, and the plant suddenly receives moisture they will split.
It is necessary to maintain constant moisture during fruiting for the best fruit set.
This article will help: https://www.gardeningknowhow.com/edible/vegetables/tomato/tomato-cracking.htm