Anytime of the year, but particularly late in the season, you have to watch out for rot on the pumpkin plant. I'm not in a humid environment, but even still, rot is a problem and it can sneak up on you. The stump, stem and pumpkin in particular are vulnerable with the amount of water we pour onto these plants.
This morning I was a little ways from the pumpkin on the stem side and decided I should scan that side because it isn't easy to see and it isn't very accessible with all the leaves around it. I noticed there were some minor cracks that were forming on the stem, that didn't really concern me, but the color was a little concerning. So I went around to the other side and leaned over the pumpkin to check it out.
I found there was a little rot forming around those cracks. So I wiped the mushy rotted stuff away (it wasn't very deep) and then took a fair amount of sulfur powder and rubbed it into the affected areas and all around it. After I got done with that, I decided to pour a 10% solution of bleach with a touch of sulfur powder in it and all over the stem area. There are some places under the stem that there wasn't enough space to get my fingers into that I wanted to make sure got hit because I couldn't be sure what was going on under there. Now I need to keep that area dry. Typically when you catch this stuff early and use a little bleach and sulfur powder it will knockthe problem right out. I lost a pumpkin once because there was a spot of rot under the stem that I couldn't see and by the time I found it I was too late. Best to check often to be safe.