What did you plant? There a few cultivars which turn yellow when ripe. Royal Golden, Golden Crown, Golden Midget, Yellow Lucky, Dianna, Funbell. Sunscald will be a spot not the whole melon turning. If you don't have a pumpkin rind type and the whole melon is turning yellow , you have a problem.

Farmerdilla, I have never grown watermelons before and I was so excited about having a in ground garden this year while I was at lowe's at just picked up a 12 pk and didn't even think about what kind they were. They were green with light yellow strips now the are turning yellow. I will pick one tonight to see. I will let you know what happened, I thought they might be sunburned because of the 100 degrees days we had.

farmerdilla, I cut one open last night and it was ripe almost to the point of over ripe, tasted good though. They were only about 2 lbs, maybe I got them mixed up with the ones that are suppose to get to 20 lbs I grew from seed. I have alot to learn, lol, I picked 4 of them last night, so everyone in my office gets a personal watermelon.

its a sign that they are getting ripe or you are about to harvest

Did u find out why they turned yellow? My sugar baby watermelons are still tiny( like an inch big) and it’s starting to turn yellow too. I’m a beginner gardener and would greatly appreciate any help. Thank you!❤️