Describe how the setting impacts the mood of the text. Use textual evidence and quotes to support your explanation.

Let's start by getting the overall mood of the poem before taking on how the setting contributes to that. Mood refers to the feelings that a text gives readers as they read a particular piece of literature. The mood of this particular piece could be described as morbid, mysterious, ominous, fearful, and/or melancholy. Over the course of the poem, readers realize that the narrator is thinking about the death of Lenore while at home alone with a creepy raven that he believes is talking to him. That is an overly simplistic overview of the poem, but it's sufficient to convey the intended mood.
Poe conveys the mood of the poem in a variety of ways, but the question specifies setting. The first line gives readers an initial time setting. The narrator tells us that he is reading at midnight. This detail helps set a scarier mood because people innately know that creepy and bad things happen at night. Humans have a natural fear of darkness, and placing the poem at midnight means that there is no chance for a friendly face dropping by with good news for tea time. The late hour is further highlighted by a knocking at the door. Readers are meant to immediately question, "Who on Earth would be visiting at midnight?"
The second stanza continues to give readers reasons to feel scared. The season is winter, which could be pleasant; however, Poe tells readers that it is "dreary." Furthermore, the man is wishing it was already morning. This tells readers that he is not currently in a happy and cheerful mood, so readers assume the opposite. Finally, the fourth and fifth stanzas enhances the dark creepiness of the setting by having the narrator open the door. He is greeted with nothing but complete darkness and silence.

That I scarce was sure I heard you”—here I opened wide the door;—
Darkness there and nothing more.

Deep into that darkness peering, long I stood there wondering, fearing,
Doubting, dreaming dreams no mortal ever dared to dream before;
But the silence was unbroken, and the stillness gave no token,