There are a few secrets to finding the tastiest and most ripe watermelon from the local grocery store or farmer’s market. First, look for a yellow spot. This may seem like a bad sign, but the yellow area shows that the melon was sitting in the field a little after it ripened, indicating that it’s super ripe, sweet, and delicious. You can also judge a watermelon by its weight. It should be heavy, no matter how large or small, indicating it’s filled with plenty of juice. And finally, knock on the surface of the melon to hear a hollow sound. If it sounds dull, it may be overripe.