Selecting a picnic worthy watermelon can be tricky when you aren't aware of the signs of ripeness. More often than not, when purchasing a watermelon from the farmer's market, the fruit will be ripe. Most farmers will harvest the melon at the peak of ripeness and if you're lucky, there will be a sample at their stand.
The same cannot be said for watermelons available at grocery store chains. There are three indicators that you should look for when selecting a ripe watermelon. First, keep an eye out for a creamy yellow spot on the underside of the watermelon. This is where the watermelon rested on the ground as it ripened. Second, the watermelon should feel heavy for its size. Per the name, watermelons are 90 percent water and the ripe ones have the most water. Lastly, give the watermelon a good knock. If it sounds hollow that's a good sign that your watermelon is sweet, juicy and ready to eat.