University of Missouri

By Linda Geist

June 30, 2025

Nothing says Fourth of July like a juicy, red slice of watermelon. That may be one reason July is observed as National Watermelon Month.

There are a few simple steps to check watermelons for ripeness and flavor, University of Missouri Extension horticulture specialist Matthew Huchteman said.

Ripe watermelons have a certain look, weight and sound. Watermelons come in a variety of sizes, colors and shapes, so find your personal favorite. Here are some things to consider, Huchteman said.

• Weight. First, watermelons are about 92% water. To find the juiciest melon, choose one that is heavy for its size compared to others.

• Field spot. Look for a large yellow or cream-colored spot on the bottom of the melon where it would have touched the ground as it grew. This indicates that the melon was ripe when harvested. “The bigger the spot, the better,” Huchteman said. “A white or pale green field spot is a sign the watermelon was harvested too early.”

• Color. The melon’s exterior rind should be dull green, and it should be firm. Avoid melons with a shine.

• Stem. The stem is also a good indicator of ripeness. If harvesting from the vine, look for the curly tendril on the stem closest to where it meets the fruit. When this tendril has dried and turned brown, the watermelon is ready to pick.

• Sound. Although this is the least trustworthy indicator, try thumping it.

“Try gently knocking on the underbelly or field spot,” Huchteman said. “A deep, thumping sound indicates ripeness. A hallow sound may mean that it is not fully ripe.”

• Smell. A sweet smell generally indicates ripeness. Stay away from watermelons with an unpleasant smell, which could mean the melon is overripe.