The setting of the novel is important first as it applies to Flaubert's realist style and social commentary and second, as it relates to the protagonist, Emma.
It has been calculated that the novel begins in October 1827 and ends in August 1846 (Francis Steegmuller). This is the time of the "July Monarchy", or the rule of King Louis Philippe I, he who strolled Paris carrying his own umbrella, as if to honor an ascendant bourgeois middle class. Much of the time and effort that Flaubert spends detailing the customs of the rural French people shows them aping an urban, emergent middle class.
Flaubert strove for an accurate depiction of common life. The account of a county fair in Yonville displays this and dramatizes it by showing the fair in real time counterpoised with a simultaneous intimate interaction behind a window overlooking the fair. The regional setting was known to Flaubert, the place of his birth and youth, in and around the city of Rouen in Normandy. His faithfulness to the mundane elements of country life has garnered the book its reputation as the beginning of the movement known as “literary realism”.
Flaubert's capture of the commonplace in his setting contrasts with the yearnings of his protagonist. Emma's romantic fantasies are foiled by the practicalities of common life. Flaubert uses this juxtaposition to reflect on both setting and character. Emma becomes more capricious and ludicrous in the light of everyday reality. Yet the self-important banality of the local people is magnified by the protagonist's yearnings. Emma, though impractical, her provincial education lacking and unformed, still reflects a hopefulness regarding beauty and greatness that seems absent in the bourgeois class.