Most of the turf across Marshall County is warm-season grass. It grows hardest through the heat of the summer, and it goes dormant and turns brown once the temperature drops. Dormant is not dead.
Dormancy is the plant standing down for the winter: top growth stops and the color goes, while the crown and roots stay alive. A lawn that browns off after the first hard cold snap is doing what it is supposed to do, and it will usually green back up from the bottom as the soil warms in spring.
It matters practically because a dormant lawn does not respond the way a growing one does. Feeding it heavily is not going to produce growth it is not in a position to make, and damage done to it in that state tends to still be there in April. The work that suits the dormant months is different work: structural pruning, bed preparation, cleanups, and planning for spring.
Alabama summers also bring their own limits. Extended heat with no rain will take even a healthy warm-season lawn off color, and how quickly it comes back depends on the depth of its root system, which is a thing built over seasons rather than over a weekend.