I live in Wisconsin and so in the summer it can get really hot. We do get decent rain, but this year has been really dry and we did not water as much as we should have.
What Is the Best Way to Grow Watermelons?
Certified GKH Gardening Expert
Watermelons need plenty of water while growing. These articles should help: https://www.gardeningknowhow.com/edible/fruits/watermelon/growing-watermelon.htm