Why does my pumpkin plant have flowers but no pumpkins?

Chef's answer
If the weather is overly hot and humid early in the season, some plants delay the production of female flowers. ... Also, too much nitrogen in the soil can result in the production of primarily male pumpkin vine flowering or even lush, healthy pumpkin vines but no flowers or pumpkins.
Frequently asked Questions 🎓
The flowers of zucchinis are a delight and knowing that you can pick off most of the male flowers and reduce vegetable production is good. Each plant will produce lots more male flowers than is needed, so harvest these each morning, leaving just one or two for pollination.
If the weather is overly hot and humid early in the season, some plants delay the production of female flowers. ... Also, too much nitrogen in the soil can result in the production of primarily male pumpkin vine flowering or even lush, healthy pumpkin vines but no flowers or pumpkins.
A few more cooking questions 📍