Summer and Fall, at the same time

I've already harvested two pumpkins as their vines died off. I have one more growing bigger than the first two, and I think another baby one going. At the same time I have at least six watermelons just around fist size out front of the house and one double that in the kitchen garden. (And I accidentally knocked a half-fist-sized one off the same vine while weeding today. :( ) And varying melons of varying sizes ripening.

Aren't pumpkins supposed to ripe in fall and melons in the summer? I mean, I love the Mediterranean climate, don't get me wrong, but this seems a little silly and backwards....