Never store a watermelon below 40 °F (4 °C), as this causes chilling injury to the the fruit. If you wish to ripen your watermelon after purchase, keep it at room temperature for a couple of days. This will ripen the watermelon slightly, but not a huge amount - this is due to the fact that when a watermelon is picked too soon it will never fully ripen.
Run the blade of the knife down the sides of the watermelon, cutting the rind from the flesh. Next cut the watermelon into round disks, then cut the disks into 1-inch cubes. If not using immediately, place the cut watermelon in a covered container and refrigerate. It will keep like this for 3 to 4 days. [4] X Research source
Now, lift off the piece you just cut out. Using a fork, scrape the seeds from the piece you just removed and from the remaining flesh on the rind. This is perfect to dice up into chunks for a snack, use in salsa, mix into drinks or anything else you would use watermelon for.
