i harvest them after the vines have died.

They are ripe you should pick them. I made the mistake of not wanting to pick orange pumpkins once because it was "too early" only to find that when I did pick them they had rotted on the underside because they were overripe and the vines weren't even dead yet. Also if you pick it now that will give the vines more energy to make you some more pumpkins. Just because it is not October doesn't mean you can't have pumpkins yet :) As a matter of fact I still have several in my living room from last season. They keep surprisingly well if stored properly.

Thanks so much for the advice. I went ahead and harvested mine. I still have several more on the vine.

Mine are sugar pumkins so they are as big now as they are supposed to get.

It is so hot and humid here that they probably stand a good chance of rotting if left out till fall.

My pumpkins haven't turned orange yet and its mid-October already. Do they have a chance? Is there anything I can do to help them?

They ripen faster in the sunlight. If there are leaves over top of the pumpkin you can either move them out of the way or simply cut them off. Have the pumpkins started turning orange at all? If they have then they will continue turning orange on their own. If there is a danger of frost you should harvest them. If they are still light green then maybe you can try fertilizing them and hope they grow faster. If they are dark green then they should start turning orange soon.