Because of Their High Water Content, Watermelons cannot be Stored in the Refrigerator.
The USDA disclosed in 2012 that it is possible to keep watermelons at room temperature for longer periods of time. Due to the fact that there are so many factors at play, this is the way things are. The rind stays intact when the temperature is between 50°F and 59°F. At lower temperatures, the rind begins to decompose and the watermelon becomes mushy.
Watermelons should not be stored in the refrigerator because of their high water content. Watermelons are composed of 92 percent water, and any additional moisture could cause them to rot and become inedible. Watermelons can be kept at room temperature for up to ten days without the need for refrigeration.