How To Tell When A Watermelon Is Ripe

A sweet, juicy slice of watermelon is one of the best things about summertime, but way too many times I’ve stared dubiously at the pile of melons at the store, trying to decide which one to choose. Often when I get home and slice it open, the melon is a disappointing light pink and not at all sweet.

How To Choose a Perfect Watermelon

The best way to tell if a watermelon is ripe is by picking it up to look for a yellowish spot underneath. “It should be dull in color and the belly or underside of the watermelon should have a creamy yellow spot,” says Carter. “This is where the watermelon sat on the ground and ripened in the sun.”

Often called the field spot or ground spot, it should be a pale, creamy, buttery yellow if it’s ripe. If the area on the underside of the melon is light green or white, that means it hasn’t quite ripened yet.

When you pick up the melon to place it in your cart, be sure to get a good idea of its weight, too. “It should be heavy for its size because watermelons are 92% water,” says Carter. If you’re not sure, pick up another watermelon that’s the same size. The one that feels heavier will likely be more ripe.

What About Thumping?

Some people suggest that you can thump on the side of the melon to determine ripeness. This may not be the most scientific method and requires a pretty good ear, but there’s some truth to the thumping method.

“A ripe watermelon will have a dull hollow sound,” says Carter. “An immature watermelon will have a higher-pitched ping sound.”

Other Things To Look For

There are a few other indicators that can help you pick a ripe watermelon.

Look for webbing, the brown, coarse lines on the side of a melon that can resemble a spider web. There’s no science to prove it, but some people believe that webbing could be caused by pollination. The more webbing, the sweeter and riper the watermelon may be.

Next, scratch the watermelon's surface lightly with your fingernail. If the rind comes away easier and reveals a white-green area underneath, it’s ripe. If you scratch a watermelon that isn’t ripe, it just leaves an indentation and darker line, according to the Ohio State University College of Food, Agricultural, and Environmental Sciences.

Finally, pick a melon that doesn’t have cuts, dents, or visible bruises. Some minor scratching is OK. “Scratches usually come from handling as harvesting is very labor-intensive,” says Carter. “Most of this is removed during grading at the packing facility, but if a scratched watermelon makes its way to retail, it’s just cosmetic.”