you know watermelons grow in NYC like snow in Miami...
Boy, do I know how that goes. Here at 5000 ft elevation we are cooler all season than many areas of lower elevation, so 75 day corn takes 100 days, etc.
It has been hit and miss growing water melons. If we happen to get an above average warm summer, I can get some good melons. Other years, not so good. Of the varieties I have tried, Charleston Grey is the best consistent producer. Right now we are looking at another week before frost. If there is no melons now there won't be.
Next time you plant melons, put them in the ground if you possibly can. Their roots will go out beyond the vine and six feet deep. Plant on the date of your last average frost in the spring. Feed them well. Don't plant near pumpkins nor winter squash. The squash will cover them up. (Don't ask how I know this.) Enjoy!
Gardening at 5000 feet elevation, zone 4/5 Northern Utah, Frost free from May 25 to September 8 +/-