I bought some cantelope plants in June. Figured they would still make fruit for mid september? So here it is late July and while I have tons of blossoms, I am not seeing any melons starting. What's up wit dat?
Cantalopes produce two types of flowers. One type has male and female parts, the other type has only male parts. so there will always be more flowers then fruit. Certain circumstances can cause them to produce only male flowers. High heat is one of them. Nematodes can also cause lots of flowers and no fruit.
But more likely, most melons require lots of water and lots of heat to really produce. Usually 2-3 months of hot weather is needed. We've only really had a month of nice hot weather. I know the growth my mini watermelon, pumpkin and butternut squash vines has exploded the last 2 or 3 weeks but before that was slow. So you probably just need more time.