Hello Rafael. Choosing a sweet melon requires paying close attention to a few distinct physical indicators at the market.
First, check the stem end. For many melons like cantaloupe, a smooth indentation where the stem used to be indicates it was harvested ripe, whereas a stem still attached often means it was picked too early.
Second, perform the smell test. Lift the melon to your nose and inhale near the stem end. You should detect a sweet, musky aroma. If there is no smell at all, the fruit is underripe. If it smells overly fermented or pungent, it is overripe.
Finally, check the weight and rind. A ripe melon should feel heavy for its size indicating high juice content. Look at the netting pattern on cantaloupes; it should be raised and coarse. For watermelons, look for a deep creamy yellow ground spot where it sat on the ground.