If we have a look at the first chapter of this incredible novel, we can see that Maycomb is above all described as a place where tradition rules and where the inhabitants are on the whole ordered by customs related to the heat. Consider the following quote:
Men's stiff collars wilted by nine in the morning. Ladies bathed before noon, after their three-o'clock naps, and by nightfall were like soft teacakes with frostings of sweat and sweet talcum.
In addition, because Maycomb is a farming county, this impacts the society of Maycomb as a whole. Consider how Atticus explains the poverty of this region to Scout:
Atticus said professional people were poor because the farmers were poor. As Maycomb County was farm country, nickels and dimes were hard to come by for doctors and dentists and lawyers.
So, Maycomb is therefore a society that is dominated by its weather conditions and also by its farming nature, in addition to having a rigid social schedule of who can associate with who and where individuals stand in the social ranking.