The heat has been horrible for me this year and has me seriously thinking about getting out of poultry. Tried of being stuck here with no break.
I have never been able to hatch in the fall because #1 I haven't thinned out the birds I've hatched in the winter through spring enough to have room to set up breeding pens
#2 I'm usually tired from the heat of summer and need a break and not ready to start in to hatching again so soon. BUT I think fall hatching is a good idea because, as you said, they will mature before summer heat hits. Also, the snakes will not be active, so you won't have to worry about them eating the chicks. Depending on the breed and how long it takes them to come into lay, fall hatched chicks may be ready to lay in spring when they naturally will lay better. Spring hatched chicks, you may not get many eggs until the following spring if they are a breed that is sensitive to the shorter day length. Then again, if you want to hatch in the fall, the birds may not be laying as well then due to molting and the shortening day length. So you may need to put them on supplemental lights to keep them laying but I wouldn't do that until after their molt. You will have to provide more supplemental heat for fall hatched chicks if you want to put them outside young, so that can be a disadvantage. I usually start hatching in January after I've had a break, had time to thin out birds, and after the holidays are over. I process turkeys for people for the holidays and that keeps me busy enough. If you are hatching to sell chicks, I've found people don't buy poultry as much during the holiday season. These are some of my thoughts.