When to Toss a Watermelon for Food Safety Reasons

Posted in Food Safety,Our Blog on August 7, 2026

Watermelon is something that is hard to beat on a hot summer day. It is sweet, refreshing and absolutely delicious. Today we look at when to toss a watermelon for food safety reasons so that you can enjoy this summer treat safely.

The Biggest Sign Your Watermelon Has Gone Bad

Visible signs of decay are the key indicators to throw it out. Really, you can allow your senses to guide you—sight, touch, taste, and smell can help you determine if your watermelon is still good to eat.

Visible mold, sliminess, or signs of decay should be treated as immediate signals to discard your watermelon.

Per the USDA, these signs indicate spoilage because the watermelon’s high water content makes it easier for the surface below the rind to be contaminated. Simply cutting away a moldy or slimy area isn’t recommended because the contamination may have spread deeper into the fruit than what we can observe.

Warning Signs in a Whole Watermelon

According to Daniel Spivey, Director of Produce Merchandising at Sprouts Farmers Market, these are the telltale signs that your uncut watermelon should be tossed:

• Visible signs of decay and mold, as well as any white, green, or black growth.
• Appearance issues like dull color, dark spots, or translucent/watery areas.
• Texture changes, such as slimy, mushy, or overly soft flesh.
• Unpleasant odor, sour, fermented, or off smell instead of a fresh scent.

Keep in mind that natural imperfections are fine, and certain spots of color on the green rind can help you know the watermelon is ripe. These are not inherently signs for when to toss a watermelon for food safety reasons.

Warning Signs in Cut Watermelon

Cues for spoilage in cut watermelon are largely the same as those for whole watermelons, including excess liquid pooling in the container. It’s important to note that cut watermelon spoils much faster than whole fruit because when you cut whole produce, a large area is exposed to air without the skin or rind to protect against microorganisms that fuel decay.

How Long Does Watermelon Last and How Should It Be Stored?

According to the USDA, watermelon stored at 50 to 60 degrees can last up to 3 weeks. Once it’s cut, you should:

• Cover the fruit in an airtight container.
• Date and refrigerate the watermelon promptly.
• Eat the leftovers the following day for the best quality.
• Toss the watermelon after 2 hours if it’s been out in the temperature danger zone (41 to 135 degrees F).

Now that you’re an expert on the shelf life of a watermelon, go ahead and enjoy this refreshing warm-weather staple.

How to Pick a Watermelon:

• A ripe, flavorful watermelon will have a creamy yellow field spot, strong stripe patterns, dry webbing spots, and feel heavy for its size.
• Use the “knock test” to listen for a deep, hollow sound, which signals juicy ripeness, and opt for rounder melons over oval ones for sweetness.
• Skip any watermelons that are shiny, soft, or unevenly shaped—dull, firm, and symmetrical is the way to go for the juiciest results.

Frequently Asked Questions

Do watermelons ripen after picking?