I'm in northern Colorado, and I never brood chicks after September, or before March. Too cold at night to keep the brooder warm enough, and they have to be in the brooder much longer than in the spring and summer, when I can put most birds outside by 3 weeks. It's just no fun watching baby birds die in the cold. Can't speak for warmer states, though.
I also know that my fertility rates drops drastically,and I go from 90-95 egg fertility in the summer, to closer to 50-60% in the fall. I've never tried winter hatching. My egg production drops this time of year, too, so I'd rather keep the eggs for sale then try to hatch them. I generally have more eggs than I can sell in early spring, which is when I incubate, and never enough in the fall, so I sell them.