When Gatsby reunites with Daisy, he's dealing with many emotions. What role does the weather play in this chapter?

Chapter Five of The Great Gatsby describes the day when Gatsby is reunited with Daisy after five years of separation, and the weather reflects Gatsby's changing mood throughout this chapter in a kind of pathetic fallacy. Pathetic fallacy is a literary device in which nature is given emotional attributes, and often adds to the atmosphere or mood of the passage.

In Chapter Five on the day Daisy is supposed to come to Nick's for tea, it is "pouring rain". Gatsby is very anxious because he wants everything to be perfect for Daisy's arrival, and he also seems very distracted. Nick describes Gatsby as "pale," with "dark signs of sleeplessness beneath his eyes." This description links to the image of the cloudy sky on this rainy day.

Just before Daisy is supposed to arrive, the weather changes from rain to mist: "The rain cooled about half-past three to a damp mist, through which occasional thin drops swam like dew." Gatsby behaves impatiently, and moments before Daisy arrives, he nearly gives up and leaves. The misty atmosphere reflects his impatient mood, and he is acting cool like the weather outside: "He looked at his watch as if there was some pressing demand on his time elsewhere." In this quote, Gatsby is being cool, behaving as though he doesn't have time to wait around for Daisy to show up and doesn't even care.

Daisy arrives like a ray of sunshine on the wet day: "The exhilarating ripple of her voice was a wild tonic in the rain." A tonic is like a medicine, so this shows that having Daisy there lifted the dreary mood like a spoonful of medicine makes one feel better when one is sick.

When Nick takes Daisy into the house, Gatsby has disappeared, only to reappear again at the front door in a puddle of rain water. This constant reference to the rain maintains a mood of dreariness, and having Gatsby wet and standing in a puddle makes him less dashing than he would probably want to be on his first reunion with Daisy, adding to his discomfort and anxiety with the situation.

Gatsby almost gives up on wooing Daisy, and he tries to leave, but Nick persuades him to stay and talk to Daisy while he goes and stands under a the umbrella of a large tree for half an hour. By this time it is pouring again, which again reflects Gatsby's uncertainty, but when Nick feels he has left them alone for long enough, the sun comes out. Before Nick even goes back into his house, readers know from the change in weather that things are going well for Gatsby and Daisy. Sure enough, when Nick reenters his living room and announces that the rain has stopped, both Gatsby and Daisy are in cheerful moods that reflect the sunshine outside:

“It’s stopped raining.”

“Has it?” When he realized what I was talking about, that there were twinkle-bells of sunshine in the room, he smiled like a weather man, like an ecstatic patron of recurrent light, and repeated the news to Daisy. “What do you think of that? It’s stopped raining.”

“I’m glad, Jay.” Her throat, full of aching, grieving beauty, told only of her unexpected joy.

Fitzgerald uses atmosphere throughout the novel to reflect the mood of the characters, and it is especially apparent in this scene with the changing weather as a backdrop to Gatsby's changing emotions.