These are popular because they're easy to select and very sweet. Ripe cantaloupes have dull yellow backgrounds with raised netting. When ripe melons are picked, the stem falls off easily, leaving a small, clean depression. After checking the stem end, flip the melon over and check the blossom end. It should be fragrant and yield a bit when pressed.
Cantaloupes are cheapest in the summer.
Since they have thick rinds, it's useless to smell them as a test for ripeness. See Santa Claus melon . The yellow ones taste better. You can buy Cranshaws while they're still a little underripe and let them sit on the counter for a few days. When fully ripe, a Cranshaw will be fragrant and yield slightly to gentle pressure at its blossom end.