Watermelons are loosely considered to be a type of melon. They have a thick, smooth, variegated green rind and juicy, sweet flesh that is usually red and dotted with small black seeds. However, watermelons come in many colors and varieties—with and without seeds.
Watermelons are available from May to September, though they're at their peak from mid-June to late August.
Yellow watermelons have pastel-yellow flesh that's just as fragrant, juicy, and sweet as red melons, but with a fine, sherbet-like flavor. Try the Yellow Crimson (it’s similar to red Crimson Sweet but even more sugary), the rarer pale-yellow Cream of Saskatchewan.
Icebox watermelons are spherical, weigh an average of 10 pounds, and are often seedless. Try Sugar Baby, which is very sweet, with firm flesh, or Mickey Lee, which has a light-green, speckled rind and deep-red flesh.
Picnic watermelons are heavy, oblong behemoths and they are the iconic Fourth of July treat. They can range anywhere from 15 to more than 50 pounds and traditionally have small to large brown-black seeds (though, these days, more and more are bred to be seedless). Look for an heirloom variety like Georgia Rattlesnake; its rind is streaked with pale-green stripes, and it has sweet, bright-pink flesh.
Mini watermelons, or “personal” watermelons, weighing up to 6 pounds, account for about 12 percent of watermelons sold. Usually seedless, with a thin, delicate rind, it’s perfect for one or two. Try Extasy—it has a striped rind and crisp, deepred flesh—or the pink-hued Little Baby Flower.
Orange watermelons are newer to the melon scene; their eye-catching color is a fun addition to fruit salads. These watermelons tend to be smaller than their red relatives, weighing in around 8-10 pounds.
Seedless watermelons are a relatively new variety, their juicy, red flesh is easy to eat because it has only a few edible white seeds. These melons can be oval or round and usually weigh between 10 and 20 pounds.
Watermelon is at its peak from June through August. At the market, look for unblemished melons that are firm with absolutely no soft or bruised spots. A ripe watermelon has a healthy sheen and a creamy yellow spot on the side that rested on the ground. Fully ripe watermelons should feel quite heavy for their size. Pick up a few and choose the heaviest melon you can find. The melon should also smell sweet and flowerlike or richly perfumed, never unpleasantly musky or slightly fermented. The stem end is the best place to smell for ripeness. If a melon has no smell, it may be underripe, so choose another. Ripe watermelons also make a hollow sound when you tap them, rather than a dull thud. Give it a thump with your knuckles and listen.
A whole watermelon should be stored in a cool place (it will better retain its flavor and texture if unrefrigerated) and will keep for about two weeks. However, if you have a ripe watermelon store it in the refrigerator and plan to use it within a few days. Take melons out of the fridge about a half hour before you plan to eat them because their sweetness and flavor will be dampened if they're too cold. Wash the outside before cutting into it to remove any bacteria. Refrigerate cut watermelon in a plastic container or zip-top bag for up to four days.